Two suicide bombings breached a wall at a military base in northwestern Pakistan before other attackers stormed the compound and were repelled in violence that killed at least 12 people and wounded 30 others, according to officials and a local hospital.

A group affiliated with the Pakistani Taliban claimed responsibility for the attack in Bannu, in Khyber Pakhtunkhwa province, and said that dozens of members of Pakistani security forces were killed. The military didn’t immediately confirm any casualties, but Bannu District Hospital said that at least a dozen people were dead. CNN reported.

The two suicide bombers blew themselves up near the wall of the sprawling military area, a security official said on condition of anonymity, because he wasn’t authorized to speak with reporters.

“After a breach in the wall, five to six more attackers attempted to enter the cantonment, but were eliminated,” the security official said