ISTANBUL — A suicide car bomber set off an explosion Saturday that demolished a bus transporting off-duty soldiers in Turkey’s central province of Kayseri, killing 13 troops and wounding 56 other people, authorities said.

Saturday’s blast comes a week after a car bomb attack claimed by Kurdish militants killed 44 people, mainly riot police, and wounded over 150 others near a soccer stadium in Istanbul.

Interior Minister Suleyman Soylu said the identity of the Kayseri attacker was known and that seven people had been taken into custody in connection with the attack. Five others are being sought.

Prime Minister Binali Yildirim said the suicide bomber ambushed a commando brigade on weekend leave in the city of Kayseri.

The Turkish army said 48 troops were among the wounded in the “treacherous attack.” The state-run Anadolu Agency said the explosion at the entrance gate to Erciyes University hit a bus transporting off-duty soldiers.

Speaking in Kayseri, Health Minister Recep Akdag told reporters 56 people had been wounded, including four who were in critical condition.

Images taken moments after the explosion showed a smoking bus, still in flames, with its windows blown open.