Security forces and hundreds of men armed with whips and clubs clashed with protesters in Kenya, with a police officer’s shooting of an unarmed bystander triggering widespread anger.

Tensions were already high in the East African country as it marked a year since massive Gen Z-led protests over the state of the economy, and the latest demonstrations were sparked by the death of a man in police custody earlier this month.

In Nairobi’s business district, the epicentre of last year’s demonstrations, small groups of protesters gathered on Tuesday, initially peacefully, to call for an end to police brutality.

But they were quickly attacked by hundreds of men on motorbikes, known in Kenya as “goons”, armed with makeshift weapons.

As shop owners hastily closed their businesses, police actively protected the armed men and fired tear gas at protesters, who responded by throwing stones and burning at least two of their motorbikes.

There was outrage after videos circulated of a police officer shooting a bystander at point-blank range in the head.

The man, who had been selling face masks, was still alive despite the severe injury.

“We handed him over to Kenyatta National Hospital, and he was taken to the ICU. He was very critical. He was still breathing,” said Vincent Ochieng, a disaster recovery officer for the Kenya Red Cross.

While the police did not directly deny any cooperation with the armed “goons”, it said in a statement it “does not condone such unlawful groupings”.

It also said the officer who shot the man in the head “using an anti-riot shotgun” had been arrested.

The government had been eager to avoid unrest this year, with its latest finance bill avoiding the tax rises that led to weeks of protests in June and July 2024.

But people have taken to the streets over the death of 31-year-old teacher Albert Ojwang in police custody earlier this month.

Protesters are demanding the resignation of a senior officer they blame for the death.

Last year’s protests peaked when thousands stormed Parliament on 25 June, where MPs were debating the unpopular finance bill.

Rights groups say at least 60 people were killed during the protests in June and July 2024, and dozens more were illegally detained by security forces in the aftermath.