SANAA, Yemen (AP) — Heavily armed militants attacked Yemen’s main prison in central Sanaa on Thursday, killing seven people and helping 29 inmates escape, many of them convicts in terrorism-related charges, the country’s state news agency reported.

The attack started with a car bomb explosion, then militants exchanged heavy gunfire with the guards at the Sanaa Central Prison, and a number of prisoners fled amid the chaos, according to SABA. A security official said authorities suspect it was an inside job.