Ukrainian security forces patrol in the northeastern city of Kharkiv on January 22, 2015
Donetsk (Ukraine) (AFP) - Pro-Russian rebels on Friday vowed to conquer more territory in eastern Ukraine and ruled out peace talks after Kiev retreated from a long-disputed airport, casting aside Europe's latest push for a truce.
The defiant comments from Donetsk rebel chief Alexander Zakharchenko came as Ukraine renewed allegations of Russian army units fighting with rebels across the frontline dividing the war-torn country's industrial east.
Western nations have branded rebel attacks in recent days as a land grab in violation of a September truce, while Washington's UN envoy dismissed Russian peace efforts as nothing more than a Moscow "occupation plan."
Moscow has strongly denied sending troops and weapons to help the rebels who now control swathes of eastern Ukraine, and accuses the West of orchestrating the downfall of the country's Russian-backed president last year.
The rebel leader in Donetsk, an insurgent stronghold and main industrial region in the heavily-Russified east of the ex-Soviet republic, said he would no longer pursue peace negotiations.
"Our side will no longer push for any more truce talks," Zakharchenko said. "We are going to advance to the very border of Donetsk province."
Sporadic shelling echoed across the rebel stronghold on Friday, and Ukraine's National Security and Defence Council chief Oleksandr Turchynov said "Russian terrorist groups" had launched a mass new offensive.
He accused Russia of "trying not only to establish control over the occupied territories, but to destroy the national identity and independence of Ukraine."
"Russian terrorist groups have essentially violated all prior ceasefire agreements... and are today assuming active offensive operations," Turchynov told a televised government meeting.
"We are talking about active units of the Russian armed forces."
- 'Fight for our land' -
The fighting came after a wave of violence on Thursday, including a trolleybus shelling that killed eight people near Donetsk's city centre, far from the front line, underlining the increasing danger facing civilians. An earlier toll of 13 dead was reduced by officials.
Moscow and Kiev traded bitter blame over the tragedy, which occurred on the bloodiest day in the conflict since an increasingly irrelevant September truce, with more than 40 people reported killed.
Rebels also captured about 20 soldiers and paraded them in front of jeering locals at the scene of the bus shelling, where the handcuffed men were targeted with snowballs and glass.
Talks in Berlin on Wednesday saw the foreign ministers of Russia and Ukraine agree to try to arrange new negotiations between Kiev and separatist commanders in the coming days to calm the conflict that has killed more than 5,000 people since it broke out in April.
But Donetsk militias are riding a string of recent successes that include the ouster of Ukrainian forces from a disputed airport on the city's outskirts earlier this week.
The airport -- long stripped of its strategic importance by heavy shelling -- had become the symbolic prize of the conflict and had seen some of the heaviest fighting.
Rebel leader Zakharchenko said any new negotiations with Kiev would only concern prisoner swaps.
"Everything happening in the Donetsk People's Republic reflects the will of the people," he said using the insurgents' title for their self-proclaimed state.
"We were born here and raised here, and we will fight for our land."
- Spiralling out of control? -
The violence has threatened to spiral out of control after a December lull that instilled hope in EU leaders that the diplomatically and economically damaging war on the bloc's eastern frontier could finally be drawing to a close.
Moscow is already under heavy US and EU sanctions over its alleged actions in Ukraine, and Western diplomats in Kiev linked the past week's spike in attacks to a reported infusion of advanced Russian artillery and equipment into the war zone.
The rebel advance comes as negotiators seek to define the confines of areas that will remain under temporary rebel control once the fighting ends.
Many in Kiev fear that the demarcation line will soon turn into an actual border splitting Ukraine from a resource-rich region that will eventually be folded into Russia.