Acting president Oleksandr Turchynov told parliament the army destroyed a base outside the town of Kramatorsk, 95 miles west of the Russian border.
In another operation, he said, troops destroyed an insurgent base in the nearby city of Slovyansk. Ukraine's defence ministry said there were no casualties.
Insurgents have seized government buildings across eastern Ukraine, fought the Ukrainian military and declared independence after the nation's crisis spilled over from a political meltdown into a military confrontation.
The Ukrainian government hosted the first round of talks intended to resolve the crisis earlier this week but ruled out meeting representatives of the insurgents.
Meanwhile, Russian Prime Minister Dmitry Medvedev said all consumers of Russian gas, including Ukraine, should abide by the simple rule that supplies should be paid for and called on energy and politics to be kept separate.