A Somalia police spokesman said a suicide car bomb by Islamic extremists has killed at least six people in the capital Wednesday.

Capt. Mohamed Hussein said most of the casualties are soldiers and more than 13 people were injured.

Somalia's extremist rebel group, al-Shabab, has claimed the responsibility for the blast, saying it targeted vehicles carrying government officials.

The car bomb exploded at a security checkpoint near the presidential palace in Mogadishu as soldiers were conducting security checks on vehicles on the main road.

Al-Shabab frequently carries out bomb blasts in the capital near the presidential compound and at hotels frequented by government officials and foreigners.