Kenya, Sept. 6 -- At least one person was killed, and three others injured on Thursday evening after al-Shabab militants ambushed a security team in Garissa County in eastern Kenya near the border with Somalia, police confirmed on Friday.

Police said the casualties were among a group of the National Police Reservists and local armed militias known as Ma'awisley, when they were ambushed at about 6 p.m. local time along the Hagadera-Biyamathobe road, adding that a member of Ma'awisley was killed during the ambush by al-Shabab gunmen who fled the area after the firefight.

"The matter is currently under investigation by the anti-terrorism police unit," police said in a security report.

Ma'awisley is a pro-government, clan-based militia opera...