NAIROBI, Kenya (AP) — At least four people were killed when Islamic extremists attacked a hotel in the Somali capital Mogadishu, a police official said Sunday.

The attack started at dawn when a suicide bomber detonated a vehicle laden with explosives at the gate of the Sahafi Hotel and then gunmen on foot shot at people in the hotel, Capt. Mohamed Hussein said.

"There's a hostage situation inside the hotel," Hussein said. Gunfire could still be heard from inside the hotel, said Hussein.

Al-Shabab, the Islamic extremist rebels waging an insurgency against Somalia's weak U.N.- backed government, claimed responsibility for the attack on a website associated with the group. Fighters from the al-Qaeda linked group infiltrated the hotel after the blast, said the statement.

Somali troops and African Union forces were at the scene of the attack, according to a post on Twitter by the African Union Mission in Somalia, which has deployed troops to bolster Somalia's government against al-Shabab's insurgency.

The hotel is often frequented by Somali government officials and business executives and it has been targeted before. Two French security advisers were abducted from the hotel by militants in 2009.