A fortified area of militants was destroyed in Sloviansk, Donetsk region, in the early hours of Thursday, Ukraine's acting president and Parliament Speaker Oleksandr Turchynov said.

"A fortified area in Sloviansk was attacked and destroyed last night," Turchynov said while opening a session of the Ukrainian parliament on Thursday morning.

"A five-kilometer area around the television tower, which broadcasts Ukrainian television to Kramatorsk, Sloviansk and other areas of Donetsk region, is fully cleansed of terrorists," he said.

Turchynov also said a covered base of militants had been destroyed near Kramatorsk.

"The terrorists' covered military base was fully destroyed in the anti-terrorist operation near Kramatorsk last night," he said.

Turchynov did not give any information on the casualties.