Donetsk (Ukraine) (AFP) - Ukraine's military accused pro-Russian fighters on Wednesday of violating a long-awaited truce at a flashpoint airport in rebel-held Donetsk just hours after it was agreed.

The sound of artillery shelling echoed across the war zone's largest city the morning after both sides promised to halt fire at the site of the deadliest fighting in the eight-month east Ukrainian conflict.

An AFP team heard several Grad rockets that appeared to have been fired from rebel-held positions just before noon local time.

"We heard the shelling but we are not afraid -- we are used to it by now," said airport district resident Oleksandr from the safety of his new apartment closer to the city centre.

"Even in my worst nightmares, I would have never imagined the things happening to us here today," he said looking out over the empty streets of a regional capital now abandoned by half of its one million residents.

Ukraine's top military spokesman said the insurgents held fire throughout the truce negotiations before relaunching their rocket strikes.

"Unfortunately, the ceasefire is not being respected," Ukrainian National Security and Defence Council spokesman Andriy Lysenko told AFP.

"Attacks on the airport and Ukrainian positions have resumed."

Local authorities reported no immediate casualties because the disputed area is not open to access by medics or local security personnel.

The rebel fighters themselves denied organising any raids on the suburban airport complex.

"Our side respected the ceasefire," a local commander told AFP under the condition that his name not be disclosed.

The airport truce was meant to take effect late Tuesday after a round of negotiations between the visiting deputy head of Russia's ground forces and a senior Ukrainian general.

Moscow's decision to dispatch such a senior commander underscored the extent of its influence over the insurgents -- a link Russia refuses to acknowledge.

Western charges of Kremlin support for the uprising and the threat of further economic sanctions are likely to top the agenda of a Thursday meeting in the Swiss city of Basel between US Secretary John Kerry and Russian Foreign Minister Sergei Lavrov.

- Lugansk truce in peril -

Another ceasefire for the entire neighbouring pro-Russian region of Lugansk had been due to go into effect on Friday.

But the local separatist leader said that his side remained unhappy with the truce terms and was seeking further talks.

"Nothing firm has been signed," Igor Plotnitsky told Russia's RIA Novosti state news agency. "We have come across issues that need further work and clarification."

The two deals were meant to reinforce a comprehensive peace deal signed by all sides on September 5 that called for a 30-kilometre (18-mile) buffer zone and granted limited self-rule to the separatists.

But hostilities only intensified after the renegade territories held their own leadership polls on November 2 that were denounced by both Kiev and the West.

- 'Patience running out' -

Ukraine's latest attempt to secure a lasting peace coincide with the creation of a new reformist cabinet that has entrusted both the finance and economy briefs to foreign investment bankers.

US national Natalie Jaresko -- the head of a private equity fund who once worked in both the US State Department and Washington's Kiev embassy -- was awarded Ukrainian citizenship hours before her confirmation by parliament as finance minister.

The economy brief will be handled by Lithuanian turned Ukrainian financier Aivaras Abromavicius -- a Swiss firm partner who admitted that Ukrainians' patience with foreigners in such sensitive posts was unlikely to last very long.

"You mention one year," Abromavicius said in response to a question about the amount of time he thought the new team had to achieve a tangible improvement in people's lives.

"I don't think we have a year," he said with a laugh. "I think that the patience will run out much quicker."