Smoke was seen rising into the air. Interior Minister Suleyman Soylu said he explosion happened during the repair of an armored vehicle in the compound. The roof collapsed. The blast also left a crater in the ground. The suggested cause of explosion was the repair work and not the result of an attack. The exact cause of the explosion was under investigation. Surrounding buildings and cars parked nearby were damaged in the blast. Diyarbakir is the largest city in the southeast of Turkey. Even accidentally, the explosion came before a hotly contested referendum on Sunday on broadening President Tayyip Erdogan’s powers, a constitutional change opposed by many in Turkey’s predominantly Kurdish southeast.