An explosion ripped through an ammunition depot of the Ukrainian army in the northern Chernigiv region early Tuesday, forcing the evacuation of 10,000 people, authorities said.

The blast occurred at about 3:30 a.m. local time (0030 GMT) at a depot near the town of Ichnya, about 170 km east of Kiev, the General Staff of the Ukrainian Armed Forces said on Facebook.

Local media reported later that the explosion triggered a fire and the subsequent massive detonation of the ammunition.

There were no immediate reports of casualties so far.

Last year, blasts occurred at three major arms storage facilities in central and eastern Ukraine.