Kenya's parliament is set to reconvene Thursday to begin the process of enacting a power-sharing agreement reached last week between the country's two main parties. But as Derek Kilner reports from Nairobi, incidents in the country's west and in the capital provided reminders of the potential for renewed violence.

In the country's western Mt. Elgon region, police continued an operation targeting the Sabaot Land Defense Force, or SLDF, a well-armed militia group blamed for a raid on two villages Monday that killed at least 12 people.

The militia has been involved in clashes in the area since 2006 that have killed hundreds and displaced tens of thousands. Members have targeted groups it says are occupying land that was unfairly taken from them in a government resettlement scheme.

Police say three militia members have been killed and at least 10 arrested. Police spokesman Eric Kiraithe says the operation will continue.

"This time around that operation must go on until those firearms being used against innocent civilians are recovered," said Kiraithe. "We expect to sustain this operation. Every time community policing approaches are applied, they just finish two or three weeks and they are back again to commit serious crimes."

This time, the police are employing helicopters and have considered calling in the military.

In a recent report the Brussels-based International Crisis Group called the SLDF the "most powerful and best-armed militia" in the country's west, and raised concerns that the group has allied itself with militias from the related Kalenjin community in driving out members of other ethnic groups.

Meanwhile, in Nairobi, police used teargas to disperse hundreds of protesters demanding the release of Maina Njenga, a former leader of the Mungiki gang, an organized crime outfit from the Kikuyu community with roots as a quasi-religious sect.

The police cracked down on the group last year after it was blamed for a wave of killings, including beheadings. But the group resurfaced during January's post-election violence, when it is believed to have killed several hundred people from other ethnic groups.

The Mungiki has long been suspected of ties to Kikuyu politicians.

While both the SLDF and the Mungiki pre-date the clashes that followed December's election, the presence of the armed groups and the potential for their mobilization highlight the possibility of future violence should the current power-sharing arrangement collapse.

President Mwai Kibaki and opposition leader Raila Odinga signed an agreement last week that calls for a coalition government that would give Mr. Odinga the new post of prime minister. The parliament is set to reopen Thursday, and will begin considering the power-sharing deal.

On Tuesday, Mr. Odinga and Mr. Kibaki agreed on a plan for reforming Kenya's constitution.