The Turkish government appears to have ruled out foul play after an explosion killed one person at a police compound in the southeastern city of Diyarbakir, days before a national referendum.
The blast on Tuesday, which caused part of the police compound's roof to collapse, occurred during the repair of an armoured vehicle, the Diyarbakir governor's office said.
It said one person had died in hospital and several others were injured.
The cause of the blast was unknown.
Diyarbakir is the largest city in Turkey's southeast, where Kurdish PKK militants have fought an insurgency for more than three decades to press demands for Kurdish autonomy.
Violence has flared since a ceasefire collapsed in July 2015.
But Interior Minister Suleyman Soylu said the explosion, which sent a large plume of smoke over surrounding buildings and left a crater in the ground, appeared to have been an accident.
"The blast was in a part of the building for riot police, where maintenance is carried out on vehicles," he was quoted by CNN Turk.
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.