A car bombing in central Turkey killed 13 soldiers and wounded more than 50 other members of the military on Saturday, the latest in a series of attacks in the country.

The attack, in the city of Kayseri, targeted a bus carrying soldiers on weekend leave, the Turkish Army said in a statement. Health Minister Recep Akdag said 56 people had been wounded in the attack, including four who were in critical condition, according to The Associated Press. The Turkish military said 48 members of the armed forces were among the wounded.

Video footage showed a bus in flames near a university campus as people tried to extinguish the fire. A wrecked car was nearby.

“I saw the explosion,” the Ihlas News Agency quoted a witness as saying. “The engine of the bus was flung. The bodies of people who died in the bus were flung, too.”