Kiev, Nov 13 (IANS/EFE): At least four Ukrainian soldiers have been killed and 18 others wounded in the last 24 hours in assaults by pro-Russian separatists in the east of the country, the Ukrainian military reported Thursday.

In a statement, the command claimed the rebels had launched 44 attacks against the government troops, violating the ceasefire agreement signed between both parties in early September.

Ukrainian authorities described as "serious" the situation in the breakaway regions of Donetsk and Luhansk, especially near the cities of Debaltsevo, Kamenki, Pavlopol, where the separatists are pounding government troops with mortar fire.

The Ukrainian forces said they still controlled the international airport of Donetsk, the main stronghold of the pro-Russian separatists.

Ukrainian Defence Minister Stepan Poltorak said Wednesday that Ukrainian troops were being redeployed in the east to counter an offensive reportedly being planned by pro-Russian militias.

Since last week, Kiev has claimed that heavy weapons convoys have been entering Ukraine from Russia by road and train, passing through border zones controlled by the separatists.

Also Wednesday, a senior UN diplomat warned that the Ukraine fighting could trigger a wider war.