Kenyan university students clashed with riot police Thursday night over the bodies of a former student leader and a slain activist who documented alleged extrajudicial killings.

It was unclear who shot former student Paul Oulu and lawyer Oscar Kingara as they were stuck in traffic outside the University of Nairobi on Thursday evening. The deaths come a week after a U.N. official accused Kenya's police of running death squads and the day that a government spokesman accused Kingara of being linked to a notorious gang.

Mobs of angry students pushed the blood spattered car into a university compound and defended it with bottles and stones, refusing to release the bodies to police because they accused them of complicity in the killings.

"What they teach us in law school, they say we should report crimes to the police. [The police] are showing us if something happens, just to reach for the gun," law student Mark Makore said as he ducked behind a wall to escape tear gas canisters and gunshots.

Government and police spokesmen did not return messages seeking comment.

The U.N. special expert on extrajudicial killings, Phillip Alston, last week accused the government of running death squads during a crackdown on the notorious Mungiki gang. He said the police commissioner and attorney general should resign immediately. The government said it would look into the accusations.

"This is a place of education, not a military camp," students shouted at the Associated Press and a member of Human Rights Watch from dormitory windows.

Students repeated Alston's demands for the resignations of top officials Thursday night, saying they had lost confidence in the country's judicial system.

"They are the judge, jury and executioner," student Caspar Sitemba said.

The deaths will further strain a coalition government already wracked by corruption scandals and accusations of impunity. More than 1,000 Kenyans were killed a year ago in weeks of riots following disputed election results.

Many were shot by police, and rights groups have accused politicians of orchestrating the violence, but although both sides agreed to share power they have yet to address the key causes of the violence or establish a tribunal to try those responsible.

The government has also been dogged by allegations of rights abuses. Several reports allege that security forces under President Mwai Kibaki executed Kenyans suspected of being members of the Mungiki gang, notorious for beheading its victims.

Kingara's organization, the Oscar Foundation Free Legal Aid Clinic-Kenya, released a report in 2007 saying more than 8,000 Kenyans had been killed or tortured to death in a crackdown against the gang and that more than 4,000 had gone missing in police custody.

The state-funded Kenya National Commission on Human Rights has also documented hundreds of extrajudicial killings linked to the Mungiki crackdown.

Police have previously dismissed the reports as fictitious and on Thursday government spokesman Alfred Mutua said the Oscar Foundation had helped organize an illegal demonstration.

Earlier in the day, public transport was stopped and two people were lynched after the Mungiki protested at the government's failure to take action over the U.N. report.