2 December 2014
Last updated at 18:34
Russian heavy armour has helped the rebels in their independence battle
The Ukrainian military says pro-Russian rebels have attacked its forces again at Donetsk airport despite a ceasefire deal earlier in the day.
The statement on Facebook said rebel shelling shattered the calm soon after both sides had ended their meeting.
Earlier the rebels reported a truce at the bitterly contested airport. And a ceasefire was agreed in nearby Luhansk region, European observers said.
Fighting has raged at the airport for three days. The rebels hold the city.
Ukraine says Russian special forces were involved in the latest Donetsk fighting, helping the separatists, who control a large swathe of eastern Ukraine.
The Kremlin has repeatedly denied Ukrainian and Western accusations that it has sent tanks and troops to the war-torn region to help the rebels.
“There was a lull at Donetsk airport during the day,” the Ukrainian military statement said, but after the ceasefire talks “the terrorists resumed attacks on the [airport] terminals”.
The statement was echoed by Russia’s Interfax news agency, which reported explosions on the northern outskirts of Donetsk on Tuesday evening.
A ceasefire deal agreed on 5 September has been violated repeatedly.
A Russian general attended the Luhansk talks, chaired by OSCE observers.
The Organization for Security and Co-operation in Europe has a monitoring mission in eastern Ukraine, where fighting has raged since the rebels seized official buildings in April.
Under the new deal for Luhansk, the sides agreed to a ceasefire starting on Friday. A withdrawal of heavy weapons from the line of confrontation was agreed for Saturday, 6 December. But it is not yet clear how wide the demilitarised zone will be.
There are some doubts about whether Cossack volunteer units operating on the rebel side will respect the ceasefire terms, Associated Press news agency reports.
But the OSCE statement said the Luhansk rebel negotiators “insisted that they were in control of all Cossack units and that these units, too, would adhere to this [ceasefire] proposal”.