Pro-Russian insurgents in eastern Ukraine have taken two government bases in battles around Luhansk.
They seized quantities of ammunition and explosives from a border guards post and taking another installation after National Guard forces ran out of ammunition.
The border guards answer directly to Ukraine’s president while the National Guard is part of the country’s police troops.
Officials said in a statement on Wednesday that six militants were killed and three Ukrainian servicemen were injured in 10 hours of fighting overnight at the National Guard base.
Rebels seized a border guards’ base on the outskirts of Luhansk following a nearly two-day-long siege.
There was no immediate report of casualties in the fighting at the border guards’ base.
Ukraine’s fledging government has blamed the recent military failures on the administration of the former President Viktor Yanukovych which, they claim, has left the army penniless and poorly trained.
The defence ministry set up a charity account to support the armed forces while volunteers across the country have been buying provisions for the soldiers.
The fighting in Ukraine’s east has escalated following the May 25 presidential election won by billionaire candy magnate Petro Poroshenko, with rebels launching an attack on a major airport and shooting down a government helicopter elsewhere.
Ukrainian troops on Tuesday launched an offensive against pro-Russian insurgents in the eastern city of Slovyansk.