AP's chief photographer and acting bureau chief for East Africa Ben Curtis was in Nairobi covering demonstrations against Kenya's electoral commission when he witnessed police kicking and beating fleeing protestors with wooden clubs. One image captured the brutality so vividly that Kenya's police chief has called for an internal investigation.

In a statement, the Kenya National Commission on Human Rights said it was "particularly dismayed by the gory scenes" as police tried to subdue protesters and said the actions by the security forces amounted to serious rights abuses. Kenyans took to social media to voice their reactions under the hashtag #stoppolicebrutality.

When riot police dispersed the opposition demonstration, much of the downtown area was covered with white clouds of tear gas. Police then went through the streets chasing protesters, beating them with sticks and clubs. In a nearby building where protesters and bystanders had taken refuge, police went into the building flushing them out toward waiting colleagues who beat many with wooden clubs and kicked them as they tried to flee.

The man seen being kicked and beaten with sticks by three separate police officers in the widely viewed video and photos, was initially reported as having died Tuesday by Kenyan media, but was later located alive in Nairobi's Kibera slum and named as 36-year-old Boniface Manono, by local radio station Capital FM.

Manono said at first he managed to escape the waiting police, he ran across the street but was pursued and collapsed against a curb. As he lay motionless on the ground the riot policeman who had pursued him beat him with a stick eight times until the stick broke in half, and then continued to kick him half a dozen times, while two other police joined in. Eventually another officer walked up and directed the police to move away, leaving Manono lying in the street.

"I thank God that I am alive. I could have died," said Manono. "When I saw the way I was kicked this afternoon actually it shocked me that it was so bad."

Monday's protest was led by former Prime Minister Raila Odinga, who lost the most recent election to President Uhuru Kenyatta. Odinga has said he doesn't believe the current election commission is credible, and is vowing to hold protests every Monday until the commissioners are removed from office.

Amnesty International urged Kenyan authorities to facilitate peaceful assembly and condemned the violence.

"The brutal beatings by police amount to arbitrary and abusive use of force, which is illegal under Kenyan, regional and international law," said Muthoni Wanyeki, a regional officer for Amnesty International.

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