MTITO ANDEI, Kenya (AP) — Seven Kenyan police officers and a civilian died Wednesday when their armored personnel vehicle ran over an improvised bomb in an attack claimed by the al-Qaida-linked extremist group al-Shabab.

A police report seen by The Associated Press said the vehicle with the Rural Patrol Border Unit in Mangai in southern Kenya had been going to refuel when the bomb exploded.

Kenyan army personnel tried to rescue the officers and came under fire from suspected al-Shabab extremists, the report said.

Seven police officers were in the vehicle, but only five bodies were found, the report said. Three bodies were later recovered in the area, the report said.

Al-Shabab claimed killing seven officers in the incident, according to the SITE Intelligence Group, which monitors extremist groups.

The incident brings to 19 the number of Kenyan police killed in the last three weeks in similar attacks. The Somalia-based al-Shabab has claimed them all.

Al-Shabab has vowed retribution on Kenya for sending troops to Somalia in 2011 to fight the extremists. Kenya is part of the African Union mission in Somalia to bolster its government from al-Shabab's insurgency.

The armored personnel vehicle in Wednesday's attack was part a fleet of 30 brought from China last year to help protect policemen manning the border with Somalia.

At the time, officers who insisted on anonymity because of fear of reprisal said the vehicles offered no protection and would put their lives in danger.