What you need to know about the recent escalation of war and humanitarian crisis in Syria

Syrian rebels andTurkish forces foughtgovernment troops in northwest Syria on Thursday asRussian warplanes struck back in a sharp escalation of an intense battle over the last rebel bastionsof Syria.

The recent escalation in fighting has left one million civilians mostly women and children to desperately flee the relentless bombing and fighting. With nowhere to go, families are sleeping outside or in thintents in sub-zero weather.

Humanitarian groups say more than 300 people, including children and babies as young as seven months old, have died just since the beginning of the year.

How we got here

The government of President Bashar al-Assad is trying to recapture the opposition-held province of Idlib.

Syrian troops backed by Russian forces have been battling since December to eradicate the last rebel strongholds in the region in a nine-year war that has killed an estimated 400,000 Syrians and left much of the country in ruins.

Rebel and jihadist groups that hold the area have been trying to overthrowAssad since 2011.

Idlib is strategically important to the government. It borders Turkey to the north and provides access via highways from the city of Aleppo to the capital Damascusandthe Mediterranean city of Latakia.

Front Burner22:01'No safe haven': The escalating crisis in Idlib, Syria

A humanitarian catastrophe is unfolding in Syria's Idlib province. Nearly one million people have been displaced since a Russian-backed Syrian government offensive began in December, forcing hundreds of thousands of people to flee to ever-shrinking camps along the border with Turkey. Today on Front Burner, we talk to CNN senior correspondent Arwa Damon, who was just in Idlib, about what she saw on the ground. These are families that have been displaced multiple times, she tells Jayme. What makes this time so much more different is that its almost as if there is a sense of finality to it theyre going to reach a point where they cant run anymore.

Turkey and Russia have closely co-ordinated their moves in recent years in Idlib province. Turkey maintains observation posts in northern Syria that were set up to monitor a 2018 ceasefire agreement with Russia. The truce collapsed in late 2019, leading to the current Syrian offensive, backed by Russia.

Russian officials have said they hold Turkey responsible for the collapse of the ceasefire deal, saying Ankara had not held up its end to rein in militants who continued attacking Syrian and Russian targets.

Turkey rejectsthe Russian assertion, saying Ankara was making progress against radical groups in Idlib when the Syrian government launched its current offensive.

Recent developments

The latest Syrian government offensive began Dec. 1.

Syrian troops supported by Russian warplanes and special forces are fighting the rebels in their strongholdsin Idlib and Aleppo provinces in what could be one of the final chapters of the nearly decade-old civil war.

Syria claims it is going after terrorists and was forced into action. But the UN saidairstrikes have hit a number of hospitals and displaced persons camps.

Nearly one million civilians have fled from airstrikes and artillery barrages toward the frontier, overwhelming relief agencies and alarming Turkey, which is struggling to cope with the 3.6 million Syrian refugees already camped inside its borders.

Ankara sent in thousands of additional troops and armoured vehicles in recent weeks, vowing to halt the government's advance.

"We are delivering our final warnings. We have not reached the desired results as yet," Turkish PresidentRecep Tayyip Erdogan said Wednesday. "The operation in Idlib is a matter of time. We could enter [Idlib]suddenly one night."

International response

The UNrefugee chief,Filippo Grandi, called for a halt to the fighting to allow hundreds of thousands of trapped and destitute civilians to move to places of safety.

UN Secretary General Antnio Guterres has called for an immediate ceasefire.

French President Emmanuel Macron called on the UNSecurity Council and European Union to take action.

"Today, and for several weeks now, one of the worst humanitarian dramas has been unfolding," Macron told reporters as he arrived at an EU summit in Brussels.

Notable quotes

"Many [civilians] are on foot or on the backs of trucks in below-freezing temperatures, in the rain and snow. They are moving into increasingly crowded areas they think will be safer. But in Idlib, nowhere is safe."

- Mark Lowcock, UN humanitarian chief

"Children and families are caught between the violence, the biting cold, the lack of food and the desperate living conditions. Such abject disregard for the safety and well-being of children and families is beyond the pale and must not go on."

- Henrietta Ford, executive director of the UN's children agency

"The sheer quantity of attacks on hospitals, medical facilitiesand schools would suggest they cannot all be accidental."

-Rupert Colville,UNhuman rights spokesperson