A Kenyan government official says four people are dead after a raid by suspected al-Shabab extremists in eastern Garissa County.

Deputy county commissioner Kibet Bowen said Tuesday the gunmen targeted police officers at a roadblock near the village of Saretho. Two of the suspected extremists were killed by police, he said.

He said the residents were killed by stray bullets during the fighting.

The al-Qaida-linked al-Shabab has vowed retribution on Kenya for deploying its troops in 2011 to fight the extremist group in neighboring Somalia.

Since December the group has increased attacks inside Kenya including Sunday's attack on a military base that killed three U.S. military personnel.