Ukraine holds on to Mariupol as civilians escaping the port city describe devastation

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• Ukraine fights off Russian control of Mariupol asZelenskysays there is 'nothing left' of the city.
  
• Kyiv residents under curfewas Ukrainian forces say they've retaken keysuburb ofMakariv.
  
• Biden warns Putin may resort to using chemical weapons in Ukraine.
  
• What questions do you have about Russia's invasion of Ukraine? Send an email toask@cbc.ca

Ukrainian forces fought off continuing Russian efforts to occupy Mariupol and claimed to have retaken a strategic suburb of Kyiv on Tuesday, mounting a defence so dogged that it is stoking fears Russia's Vladimir Putin will escalate the war to new heights.

"Putin's back is against the wall," said U.S. President Joe Biden, who is heading to Europe this week to meet with allies. "And the more his back is against the wall, the greater the severity of the tactics he may employ."

Biden reiterated accusations that Putin is considering resorting to using chemical or biological weapons, though Pentagon spokespersonJohn Kirby said the U.S. has seen no evidence to suggest that such an escalation is imminent.

The warnings came as attacks continued in and around Kyiv and Mariupol, and people escaped the battered and besieged port city.

Ukrainian President Volodymyr Zelensky accused Russian forces of not only blocking a humanitarian convoy trying to take desperately needed aid to Mariupol but seizing what another Ukrainian official said were 15 of the bus drivers and rescue workers on the aid mission, along with their vehicles.

Zelenskysaid the Russians had agreed to the route ahead of time.

"We are trying to organize stable humanitarian corridors for Mariupol residents, but almost all of our attempts, unfortunately, are foiled by the Russian occupiers, by shelling or deliberate terror," he said in his nightly video address to the nation.

The hands of one exhausted Mariupol survivor were shaking as she arrived by train in the western city of Lviv.

"There's no connection with the world. We couldn't ask for help," said Julia Krytska, who made it out with her husband and son with the help of volunteers. "People don't even have water there."

Explosions and bursts of gunfire shook Kyiv, and black smoke rose from a spot in the north. Intensified artillery fire could be heard from the northwest, where Russia has sought to encircle and capture several suburban areas of the capital, a crucial target.

Early Tuesday, Ukrainian troops drove Russian forces from the Kyiv suburb of Makariv after a fierce battle, Ukraine's Defence Ministry said. The regained territory allowed Ukrainian forces to retake control of a key highway and block Russian troops from surrounding Kyiv from the northwest.

A video posted by Ukrainian police showed them surveying damage in Makariv, including to the town's police station, which an officer says took a direct hit to its roof. The police drove by destroyed residential buildings and along a road pocked by shelling. The town appeared all but deserted.

Still, the Defence Ministry said Russian forces partially took other northwest suburbs, Bucha, Hostomel and Irpin, some of which have been under attack almost since Russia invaded nearly a month ago.

WATCH | Doctor anguished over bombing of psychiatric hospital in Mykolaiv:

Tearful doctor rails against bombing of Ukrainian psychiatric hospital

2 years ago

Duration 0:44

Dr. Anatolii Pavlov expressed anger at the 'cruelty' of the Russian bombing of his psychiatric hospital in the Black Sea port of Mykolaiv, Ukraine.

A Western official, speaking on condition of anonymity to discuss military assessments, said Ukrainian resistance has brought much of Russia's advance to a halt but has not sent Moscow's forces into retreat.

"We have seen indications that the Ukrainians are going a bit more on the offensive now," Pentagon press secretary John Kirby separately told reporters in Washington. He said that was particularly true in southern Ukraine, including near Kherson, where "they have tried to regain territory."

Asked on CNN what Russian President Vladimir Putin had achieved in Ukraine, Kremlin spokesman Dmitry Peskov said: "Well, first of all, not yet. He hasn't achieved yet." But he insisted that the military operation was going "strictly in accordance with the plans and purposes that were established beforehand."

Putin's aims remain to "get rid of the military potential of Ukraine" and to "ensure that Ukraine changes from an anti-Russian centre to a neutral country," Peskov said.

Russia's far stronger, bigger military has many Western military experts warning against overconfidence in Ukraine's long-term odds. Russia's practice in past wars in Chechnya and Syria was to grind down resistance with strikes that flattened cities, killed countless civilians and sent millions fleeing.

But Russian forces appeared unprepared and have often performed badly against Ukrainian resistance. The U.S. estimates Russia has lost a bit more than 10 per cent of the overall combat capability it had at the start of the fight, including troops, tanks and other materiel.

Western officials say Russian forces are facing serious shortages of food, fuel and cold weather gear, leaving some soldiers suffering from frostbite. Ukrainians have reported hungry soldiers looting stores and homes for food.

10 million people displaced

Theinvasion has driven more than 10 million people from their homes, a number similar to the population of Portugal and almost a quarter of Ukraine's pre-war population, according to the United Nations.Thousands of civilians are believed to have died. Estimates of Russian military casualties vary widely, but even conservative figures by Western officials are in the low thousands.

On Monday, Russia's pro-Kremlin Komsomolskaya Pravda newspaper, citing the Defence Ministry, reported that almost 10,000 Russian soldiers had been killed. The report was quickly removed, and the newspaper blamed hackers. The Kremlin refused to comment. The same Western official said the figure was "a reasonable estimate."

Nuclear fears

Beyond the terrible human toll, the war has shaken the post-Cold War global security consensus, imperilled the global supply of key crops,including wheat, and repeatedly raised worries it could set off a nuclear accident.

Ukraine's natural resources minister said wildfires near the Chornobyl nuclear power plant in northern Ukraine have been extinguished and radiation levels in the area are within norms. Fires are not uncommon in the area, but raise concern about the potential release of radiation from fallout from the 1986 explosion and fire at the plant.

Concerns have been expressed about safety at the decommissioned plant since it was seized by Russian forces last month. The power supply was temporarily cut amid fighting earlier this month, and Ukraine's nuclear regulatory agency said Monday that radiation monitors around the plant had stopped working.

WATCH |Biden warns Russia'sattacks could get worse:

Biden warns Putin may be preparing to use chemical weapons in Ukraine

2 years ago

Duration 7:30

U.S. President Joe Biden says that Russian President Vladimir Putin, with his 'back against the wall,' is preparing 'new false flags' in Ukraine and could deploy biological and chemical weapons.

Facing unexpectedly stiff resistance,Russian President Vladimir Putin's forces are increasingly concentrating their air power and artillery on Ukraine's cities and civilians living there.

Talks to end the fighting have continued by video. Ukrainian President Volodymyr Zelensky has said he would be prepared to consider waiving any bid by Ukraine to join NATO a key Russian demand in exchange for a ceasefire, the withdrawal of Russian troops and a guarantee of Ukraine's security.

UNSecretary-General Antonio Guterres said he saw progress in the talks.

"From my outreach with various actors, elements of diplomatic progress are coming into view on several key issues," and the gains are enough to end hostilities now, he said. He gave no details.

WATCH |UN secretary-general says fighting must end:

Russia needs to end 'absurd' war in Ukraine, says UN chief

2 years ago

Duration 0:49

UN Secretary General Antnio Guterres urged Russia to end its war in Ukraine now, saying it is inevitable that it will move 'from the battlefield to the peace table.' 'This war is unwinnable,' he said.

The Western official, though, said that there were no signs Moscow was ready to compromise.

Zelenskyalso suggested Kyiv would be open to future discussions on the status of Crimea, which Russia seized in 2014, and the regions of the eastern Donbas region held by Russian-backed separatists. But he said that was a topic for another time.

Scope of human toll inMariupol unclear

As part of a series of addresses to foreign legislatures to drum up support for Ukraine, Zelenskyspoke to Italian lawmakers on Tuesday, telling them that the besieged port of Mariupol had been utterly destroyed in the Russian onslaught. He also spoke to Pope Francis.

"Imagine a Genoa completely burned down," he said to rapt lawmakers, citing an Italian port city of a similar size. Mariupol officials said on March 15 that at least 2,300 people had died in the siege.

Accounts from the city suggest the true toll is much higher, with bodies lying uncollected. Airstrikes over the past week devastated a theatreand an art school where many civilians were taking shelter.

Zelensky, in his video address, said more than 7,000 people were evacuated from Mariupol on Tuesday. But about 100,000 remain in the city "in inhuman conditions, under a full blockade, without food, without water, without medicine and under constant shelling, under constant bombardment," he said.

Zelensky also spoke again by phone to Prime Minister Justin Trudeau Tuesday ahead ofupcoming NATO and G7 meetings. The prime minister's office said Trudeau reiteratedCanada's "steadfast support for the territorial integrity, sovereignty, and independence of Ukraine, and vowed to continue to back Ukraine wholeheartedly."

Trudeau leaves for Brussels Tuesday evening to take part in the international meetings.

Like Zelensky, the Red Cross said a humanitarian aid convoy trying to reach the embattled city with desperately needed supplies still had not been able to enter.

• This Russian teacher refused to show kids propaganda about Ukraine. It cost him his job

Perched on the Sea of Azov, Mariupol is a crucial port for Ukraine and lies along a stretch of territory between Russia and Crimea. As such, it is a key target that has been besieged for more than three weeks and has seen some of the worst suffering of the war.

WATCH |Mariupol refugee recounts life in city under siege:

Mariupol refugee describes escape from city under siege

2 years ago

Duration 4:25

Artur Shevchenko describes what it was like to shelter in Mariupol, Ukraine, with his family during the Russian attacks, and how they were able to escape the city.

But it's not clear how much of the city it holds, with fleeing residents saying fighting continues street by street.

A senior U.S. defence official, speaking on condition of anonymity to give the Pentagon's assessment, said Russian ships in the Sea of Azov were shelling Mariupol. The official said there were about seven Russian ships in that area, including a minesweeper and a couple of landing vessels.

Ukraine's Defence Ministry said that troops defending the city had destroyed a Russian patrol boat and electronic warfare complex. Britain's Defence Ministry said Ukrainian forces "continue to repulse Russian attempts to occupy" Mariupol.

Those who have made it out of Mariupol told of a devastated city.

"They bombed us for the past 20 days," said 39-year-old Viktoria Totsen, who fled into Poland. "During the last five days the planes were flying over us every five seconds and dropped bombs everywhere on residential buildings, kindergartens, art schools, everywhere."

Canada has already received more than 20,000 applications for authorized emergency travel from Ukraine, according toImmigration, Refugees and Citizenship Canada.