Five soldiers and at least 13 civilians, including women and children, were killed in a twin suicide bombing Tuesday that targeted a military compound in northwestern Pakistan, according to the military.

The attack in Bannu district in Khyber Pakhtunkhwa province injured at least 32 others, the military’s media wing, Inter Services Public Relations (ISPR), said in a statement Wednesday.

“The assailants sought to breach the cantonment’s security,” the ISPR said. “The attackers rammed two explosive-laden vehicles into the perimeter wall,” after the security forces responded to the intrusion.

The military said five soldiers died in the ensuing gun battle that killed 12 militants. Four suicide bombers were also killed.

Most of the civilian casualties occurred as buildings, including a mosque and a residential compound, collapsed with the force of the blasts.

“The multiple suicide blasts resulted in the partial collapse of the perimeter wall, causing damage to the adjacent infrastructure,” ISPR said.

The Associated Press reported that a relatively lesser-known militant group, Jaish Al-Fursan, claimed responsibility for the attack.

The military said Afghan nationals were involved in the attack. It said ring leaders of the Khawarij, an Arabic term the military uses to describe fighters of the Pakistan Tehreek-e-Taliban, planned and executed the attack from Afghanistan.