A massive suicide car bomb attack on an army training camp in Yemen’s second city of Aden killed at least 60 people on Monday, medical sources said. The blast was claimed by ISIS.

A security official told Agence France Presse that the attacker drove his vehicle laden with explosives into a gathering of new recruits at the camp in northern Aden.

The assault killed 60 people and wounded 29 others, medical sources from the three hospitals where the victims were taken told AFP.

A security source told Reuters the attack targeted a school compound where conscripts of the Popular Committees, forces allied to the internationally recognized President Abd-Rabbu Mansour Hadi, were gathered for breakfast.

The blast rocked the area and sent debris flying, sending residents fleeing, one witness said.

The port city, the temporary base of Yemen’s Gulf-backed government, has seen a wave of bombings and shootings targeting officials and security forces.

Attacks in Aden are often claimed by jihadists from either Al-Qaeda or ISIS, which have both taken advantage of the chaos in Yemen to make gains in southern and southeastern regions.

ISIS claimed responsibility for Monday’s bombing and said the attack killed about 60 new recruits, according to the group’s Amaq news agency.

“Around 60 killed in a martyrdom operation carried out by an ISIS militant that targeted a recruitment center in Aden,” Amaq said in a statement published on Twitter.

Yemeni authorities have trained hundreds of soldiers in Aden over the past two months as part of operations to retake neighboring southern provinces from jihadists.

Earlier this month, Yemeni government forces backed by the Saudi-led coalition entered Abyan’s provincial capital Zinjibar.

Troops retook other towns across Abyan.