Unidentified gunmen have killed a Kenyan Muslim cleric who was accused of supporting Somali militant group al-Shabab.

Kenyan police say Aboud Rogo Mohammed was shot dead Monday in the port city of Mombasa. Initial reports say the gunmen attacked the cleric as he was driving a vehicle carrying his wife and family.

Aboud Rogo Mohammed was placed on a U.S. sanctions list last month for allegedly recruiting fighters and raising money for al-Shabab.

The U.N. Security Council placed its own travel ban and assets freeze on the cleric, saying he used an extremist group, Al Hijra, as a way of recruiting Swahili-speaking Africans to fight in Somalia.

Al-Shabab is fighting to overthrow Somalia's U.N.-backed government. The militant group is known to have supporters in Kenya, which has a large Somali immigrant community.

Kenyan forces entered Somalia last October to fight al-Shabab, and have since joined the African Union peacekeeping force in the country.