Gunmen opened fire on a Ukrainian military unit in the Donetsk region overnight, Ukraine's Defense Ministry said Thursday, CNN reports.

One Ukrainian solder was injured in the assault in the town of Artemivsk, the ministry said in a statement.

Security forces responded and fought off the attack. The military facilities are under the control of the Ukrainian army, the ministry said.

Ukraine's Interior Minister Arsen Avakov said on his Facebook page that the group of about 70 attackers were pro-Russian militants.

He accused them of trying to take weapons from the military unit.

In the eastern city of Mariupol, the military has retaken control of the city hall in the eastern Ukrainian city of Mariupol, the interior minister said Thursday.