Updated

A bomb exploded in a piece of luggage at an airport in a central Somali town, wounding three people, a police official said Monday.

The bomb went off at a checkpoint as soldiers searched through bags before passengers were allowed to board, said Ahmed Nur, a police official in the town of Beledweyne, where the incident happened Monday. An African Union peacekeeper was among the wounded, he said.

Somalia's Islamic extremist rebels, al-Shabaab, claimed responsibility for the blast.

Last month a bomb exploded aboard a commercial passenger jet, creating a hole in the fuselage, blowing out the suspected bomber and forcing the plane to make an emergency landing in Mogadishu. Al-Shabaab claimed responsibility for that attack.

Al-Shabaab, which is allied to Al Qaeda, is waging an insurgency against Somalia's United Nations-backed government, carrying out deadly attacks in the capital, especially public places frequented by government officials, soldiers and foreigners. Hotels in Mogadishu are often targeted.

Al-Shabaab has also carried out attacks on neighboring countries that contribute troops to the African Union peacekeeping force bolstering the Somali government against the extremists.