A suspected recruiter for the Somalian militant group al Shabaab shot dead at least four Kenyan policemen in the station where he was being held on Thursday after he snatched a weapon from a guard, police said.
The suspect is now holding other prisoners as hostage and police have surrounded Kapenguria police station in west Kenya, police inspector general Joseph Boinnet said in a statement.
The man is suspected of links to terrorism, it said, without being more specific. The number of casualties is not clear, the statement said.
Another police officer, who declined to be name, told Reuters at least four officers were killed and that figure could rise.
Al Shabaab has launched a series of attacks against Kenya in recent years, including using local recruits. The group says the attacks are aimed at driving Kenyan forces out of Somalia, where they are part of an African force fighting al Shabaab.
Kenyan television channel KTN said as many as six officers had died in the continuing stand-off in Kapenguria.
Boinnet said that police had also repulsed an attack by al Shabaab militants on a camp in the Lamu region of eastern Kenya, near the Somali border.
Several militants were believed to have been killed or escaped with severe injuries from that assault. He did not give figures.