Fighting was taking place on Tuesday in the centre of Luhansk, near Ukraine`s border with Russia, between government forces and separatist rebels who have held the town since April, a Ukrainian military spokesman said.
Russia on Monday said all objections to it sending a humanitarian convoy to Ukraine had been resolved but said no progress had been made in Berlin talks toward a ceasefire between government and rebel forces in the east of the country.
Following Russia`s stand off over Ukraine, Western nations imposed sanctions on Moscow including on its financial and energy sectors, and put dozens of Russians close to President Vladimir Putin on a sanctions list.
A military statement said it suspected the rebels had fired back with a powerful Russian-made Uragan missile system south east of Donetsk near the village of Novokaterinivka, their first use of the weapon.
Ukrainian forces have raised their national flag over a police station in the city of Luhansk which was for months under rebel control, Kiev said on Sunday, in what could be a breakthrough in Ukraine`s efforts to crush pro-Moscow separatists.
If Russia tries to infiltrate troops into a NATO country, even out of official military uniform as it did before it annexed Ukraine`s Crimea, NATO will respond militarily, the alliance`s top commander said in an interview published on Sunday.
Heads resting on their bags as they wait in stifling heat in their van, 11 women sit stranded at the Ukrainian border as a dispute over a mammoth Russian aid convoy blocks their mission to reach relatives stuck inside besieged Lugansk.
Moscow and Kiev`s foreign ministers geared up for an urgent meeting with their French and German counterparts Sunday as Ukraine`s boasts that it had destroyed a small military convoy from Russia ramped up the stakes.
Ukraine`s crisis entered dangerous new territory on Saturday with Kiev claiming its forces destroyed a Russian military convoy, while the US warned Moscow over its "provocative" efforts at destabilisation.
Ukrainian forces and pro-Russian separatists fought skirmishes near the Russian border on Saturday but there was no sign of the conflict widening after Kiev said it partially destroyed an armoured column that had crossed the border from Russia.