1,000 pro-Russian rebels in tank offensive on east Ukrainian town

Ukraine's defence forces have accused pro-Russian separatists in the country's east of "cynically ignoring" the ceasefire as artillery fire, rebel tanks and as many as 1,000 fighters have been reported advancing on two populated areas in Ukraine's Donetsk region.

The recent buildup of Russian arms on the Ukrainian border has prompted fears that the pro-Russian forces in the country's east will soon launch an offensive, disrupting the relative calm that has been in place since February. Rebel leader Alexander Zaharchenko said last week that he intended to "liberate" three more towns which are currently under Kiev's control.

Both Ukraine and the pro-Russian fighters in eastern Ukraine's Donetsk region have confirmed reports of artillery fire breaking out west of the city of Donetsk, near the town of Marinka. However, both sides have blamed each other for starting the violence.

The general staff of the Ukrainian forces involved in fighting in the east (ATO) reported that separatist fighters began a major advance against several Ukraine-held positions at 4am today, most notably near the towns of Marinka and Krasnogorovka. According to the ATO press statement, the separatists sent over 10 tanks and up to 1,000 soldiers to fight Ukrainian forces near Marinka, under the cover of 2C1 Gvozdika self-propelled guns.

The statement highlights that the rebel advances were accompanied with mortar shelling and the use of heavy weapons, despite the fact they are meant to be kept at least 25 kilometres from the frontlines in accordance with the ceasefire agreement signed in Minsk, Belarus in February. In response, Ukraine's defence forces pushed artillery forces toward the frontline, to repel the attack, they said.

"In order to prevent the enemy advance and avoid losses among our servicemen, the Ukrainian command, after notifying all international partners, was forced to use artillery which were recalled from their stations behind the frontlines in accordance with the Minsk agreement," the statement read.

Citing sources from the ATO, Ukrainian online newspaper Ukrainskaya Pravda reports that seven Ukrainian servicemen were wounded, while 15 rebels were reportedly killed. ATO press secretary Alexander Poronyuk told the paper that skirmishes near Marinka continued throughout today though not on the scale of this morning's artillery fire.

Independent Russian news agency Interfax reported that 18 Ukrainian servicemen had been wounded, 12 of whom were taken to hospital in Dnepropetrovsk, and one had been killed. Volunteer doctor Armen Nikohosyan told Ukrainian television's Hromadske.TV channel that 25 Ukrainian soldiers have been wounded.

Meanwhile the Donetsk separatist group, which refers to itself as Donetsk People's Republic (DNR), accused Ukraine of starting today's fighting, calling their use of artillery "provocation" which could lead to war and denying that the rebels are attacking Marinka.

Speaking to Russian news agency Ria Novosti Vladimir Kononov who describes himself as the minister of defence of DNR said: "This is provocation with the intention of blaming us in attempting to take Marinka."

"Marinka is our territory anyway," he added. "Such provocations could lead us to war. This is a violation of the Minsk agreement."

Official spokesman of the ATO, Andriy Lysenko, said in his regular Wednesday press conference that Ukraine's defence forces had noticed increasing night-time movement from the rebel fighters in the east, however he ruled out that today's fighting was the start of a wider advance on more Ukrainian territories.