Kenyan police say they have killed four men described as most-wanted extremist suspects whose names were released to the public in December.

Matawa Muchangi, chief of police in the coastal town of Malindi, where the shootout happened, said one of the victims is Suleiman Mohammed Awadh, who was wanted for his alleged role in several Islamic extremist attacks, including the mass killings on a college campus in Garissa in April.

He said: "The four were shot dead when they engaged our officers on a shootout and even threw grenades at them."

He said police recovered explosives, arms and mobile phones as well as maps.

Kenya has been attacked several times by Islamic extremists with ties to the Somali extremist group al-Shabab, which opposes Kenya's military involvement in Somalia.