KIEV/NOVOLUHANSKE, Ukraine (Reuters) - Ukraine and pro-Russian separatists accused each other on Thursday of ramping up attacks in their conflict as the Ukrainians reported three servicemen killed in the worst fighting of 2018.

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Apart from the three killed, three others were also wounded in fighting in the past 24 hours, Ukrainian military spokesman Oleksander Motuzyanyk said.

A Russia-backed insurgency erupted in Ukraine’s industrialized east in 2014 and the bloodshed has continued despite a ceasefire deal brokered by Germany, France, Russia and Ukraine.

More than 10,000 people have been killed in the conflict, with casualties reported on a near-daily basis.

The separatist side “more and more cynically and brazenly is increasing both the intensity and density of its firing,” Motuzyanyk said in a televised briefing.

He said one of the servicemen was killed in separatist shelling near the government-controlled village of Novoluhanske.

In the early hours of Thursday, a Reuters witness in Novoluhanske saw Ukrainian troops firing artillery towards rebel positions in an apparent response to the attack.

“It’s clear we can’t stand such things from the enemy,” an artillery commander in a pro-Ukrainian militia group called Donbas Battalion told Reuters, calling himself by his nom de guerre Hayduk.

The rebel leadership meanwhile accused Ukraine of using artillery to attack the separatists for the first time since the New Year, separatist news website DAN reported.

Under the 2015 Minsk peace agreement, all heavy weapons were meant to have been withdrawn, but ceasefire monitors regularly report violations of this and other terms of the deal on both sides of the front line.

In an effort to end the deadlock, the international community, including the United States, has called for the deployment of U.N. peacekeepers in the Donbass region.

Both Kiev and Moscow back the idea but disagree on whether the troops should be positioned on the rebel-controlled part of the Ukraine-Russia border, and no decision has been made.

Russia denies accusations from Ukraine and NATO that it supports the rebels with troops and weapons.