DONETSK (AFP) - Intense battles raged on Friday around the airport in the main stronghold of pro-Kremlin insurgents as Ukraine's new leader laid out tough terms for a ceasefire demanded by his European allies and Russia.
An AFP team outside Donetsk International Airport - a gleaming hub shuttered since coming under a bloody rebel attack at the end of May - saw exchanges of fire and an anti-aircraft missile being shot at a Ukrainian military jet.
"Here we go again. This is just like yesterday," said one vendor from a nearby outdoor market as dozens of people looked nervously up at the cloudy sky.
"Everything is shutting down," said another man in his fifties who was preparing to escape across the border to Russia with his daughters and grandchildren.
"There is nothing to do here. No work - and it is getting too dangerous," he said.
Pro-Kiev authorities in Lugansk also said four miners were killed and 16 injured when their bus came under artillery fire on Thursday.
But government forces reported making significant progress in their attempts to choke the encircled pro-Russian gunmen off from what they allege are vast quantities of Russian weapons supplies.
"At least 50 rebels were wiped out in the past 24 hours," a Ukrainian military spokesman Vladyslav Seleznyov wrote in a Facebook post.
A spokesman for Ukraine's national security and defence council added that at least four servicemen were killed and 25 wounded in a barrage of rebel attacks.
The tide in Ukraine's worst crisis since its 1991 independence turned last weekend when resurgent government forces managed to flush out the separatists from a string of eastern towns and cities they had seized in early April.
Most of the militias have since retreated to Donetsk and the neighbouring industrial city of Lugansk - both capitals of their own "People's Republics" that refuse to recognise Kiev's new West-leaning government and are seeking annexation by Russia.
The conflict has claimed the lives of more than 500 people, while Amnesty International also said there had been "hundreds" of abductions and acts of torture committed by the separatists.
An Amnesty report published Friday also said that "excessive force may have been used... by Ukrainian forces" on several occasions - a charge repeatedly made by Moscow.
Ukrainian President Petro Poroshenko now finds himself trapped between European pressure to agree an immediate truce and massive domestic support for his troops to finish off an insurgency that has threatened the 45-million-strong nation with disintegration and economic collapse.
Germany and France have been spearheading EU efforts to secure a truce and win promises from the Kremlin to stop meddling in Ukraine. They hope to avoid further European sanctions on Russia that might damage their energy and financial ties with Russia.
But they have found Poroshenko - boosted by recent successes on the battlefield and bound by promises made at the May election - looking increasingly unwilling to call off the offensive.
President Vladimir Putin has also refused to call on the rebels to disarm. The West sees that as a sign the Kremlin leader is intent on keeping the Ukrainian government destabilised as punishment for ruining his plans to fold the country into a new post-Soviet alliance.
German Chancellor Angela Merkel - fresh from a joint call with Putin and French President Francoise Hollande - tried her luck once again on Thursday with Poroshenko in an exchange that made no reported progress toward a truce.
The Ukrainian leader's website said Poroshenko "pledged his commitment to a bilateral ceasefire" but he also laid out a series of conditions that Merkel appeared to suggest were impossible for Europe to implement while the fighting raged on.
Poroshenko specifically asked Western powers to help "monitor and verify the bilateral ceasefire, and help establish control of the border that can halt the supply of weapons and gunmen from Russia".
The Ukrainian statement said Merkel told Poroshenko that monitors from the Organisation for Security and Cooperation in Europe (OSCE) who would bear the brunt of such a mission "have no access to border crossing because of the militias' activities".