Ukraine has accused pro-Russian rebels of carrying out the heaviest artillery attacks on government positions in six months and warned of signs the conflict was escalating despite a ceasefire deal.

Petro Poroshenko, the Ukrainian president, said about "200 insurgents used tanks to storm" Novolaspa - a village halfway between the separatists' de facto capital Donetsk and the Kiev-held port of Mariupol - in a pre-dawn raid that caught government soldiers off guard.

The rebels denied attacking government troops and signalled that they had always had militia units stationed in Novolaspa, the AFP news agency reported.

"The armed forces of Ukraine simply put the village under a heavy shelling attack," a local separatist official told the rebels' main news site.

"Novolaspa remains under the control of the People's Republic of Donetsk."

Ceasefire violated

A ceasefire deal, signed in mid-February, has failed to stem the violence in the eastern conflict zone. Both sides regularly accuse the other of violating the terms of the peace agreement and casualties are reported almost daily.

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Control of Mariupol could help the rebels form a corridor to the Crimea peninsula, which Russia annexed from Ukraine last year.

"This brazen attack by the occupiers took place against a background of an escalating situation in east Ukraine," military spokesman Andriy Lysenko said, describing rebel shelling in the past 24 hours as the heaviest since a battle for the town of Debaltseve in February.

Kiev on Monday also reported the death of one soldier while the separatists accused government forces of killing a civilian in the rebel-held area of Gorlivka.

The Ukrainian military told the Reuters news agency that 400 rebel fighters supported by tanks had also attacked government forces around the village of Starohnativka, 50km north of Mariupol.

General Viktor Muzhenko, the chief of staff of the Ukrainian army "informed the president that the Ukrainian forces gave a fitting rebuff and repelled all the attacks," the presidency said.

But the defence ministry later reported the rebels mounted a second attack on the same village whose outcome was not immediately clear.

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There were also reports of shelling in the village of Golmovsky, near Donetsk.

"Ignoring the truce agreements, our enemies are continuing to stage provocations that are meant to escalate the conflict," the defence ministry said in a statement.

The Ukrainian foreign ministry called the clashes "a dangerous indication of a further escalation to come".

Source: AFP And Reuters