NAIROBI, Kenya (AP) — Kenyan police say they have arrested three men who tried to force their way into a British Army training camp on the same day that al-Shabab extremists attacked a military base and killed three U.S. military personnel.

The internal police report seen by The Associated Press says the three “terrorist suspects" were arrested Sunday after trying to enter the British Army Training Unit in Laikipia county. It occurred around the same time as the al-Shabab assault on the base in Lamu county.

The British government was not immediately available for comment.

Al-Shabab's assault at the Manda Bay Airfield lasted several hours and destroyed several U.S. aircraft and vehicles. The airfield is adjacent to Camp Simba, a key Kenyan military base used by U.S. counterterror forces.

No Kenyans died in the attack, Kenya's military spokesman Paul Njuguna said Monday.

Al-Shabab, which is linked to al-Qaida, has vowed retribution on Kenya for its troop presence in Somalia to counter the extremist group.