Pro-Russian militants fire Kalashnikov assault rifle during the funeral of Vasily Burov, 46, at a cemetery in the eastern Ukrainian city of Makiyivka, near Donetsk, on May 31, 2014. Burov was killed in combat with Ukrainian troops in Gorlovka, a small city in the Donetsk region, on May 29. Ukraine accused Russia on on may 31 of unleashing a mass propaganda campaign to persuade global powers not to recognise an election that gave the presidency to a pro-Western tycoon. AFP PHOTO/ VIKTOR DRACHEV (Photo credit should read VIKTOR DRACHEV/AFP/Getty Images)

By Thomas Grove and Gabriela Baczynska

DONETSK, Ukraine, May 31 (Reuters) - Ukrainian separatist leader Denis Pushilin said on Saturday six rebels had been killed while trying to collect the bodies of comrades who had died under Ukrainian army fire earlier this week close to Donetsk airport.

Ukrainian forces regained control of the airport in the east of the country on Monday, killing at least 50 separatists, after a Sunday presidential election which gave billionaire Petro Poroshenko an overwhelming victory.

It was the first time the Ukrainian side had unleashed its full force on the pro-Russian two-month rebellion, caused partly by the ouster of a Moscow-friendly president and the annexation of the Crimean peninsula by Russian troops.

"They died trying to take back the Ukrainian airport, and our boys were trying to get their bodies out," Pushilin said over the telephone, without giving further details of the violence. He said the six had died during the day on Friday.

Though fighting has died down for now in Donetsk, the stand-off over the city airport remained unresolved on Saturday with amateur video footage showing a cargo plane taking off and releasing decoy flares as it was fired at from the ground.

Regional newsagency Interfax cited the prime minister of the self-styled Donetsk People's Republic as saying the separatists will ask the International Red Cross to remove corpses by the aiport. It was unclear how many remained.

A spokesman for the Kiev-led "Anti-terrorist operation" or ATO said earlier in the day two new attacks on the airport had been repelled by Ukrainian forces with no injuries to their side, Interfax reported. It was not clear whether the attacks were in fact attempts by separatists to clear bodies.

In Donetsk itself, 2,000 people gathered in the city's central Lenin Square on Saturday, waving Russian flags and chanting "Russia! Russia!" in support of the self-proclaimed republic, which has sought help from Moscow.

"I have no other objective but to make Donbass a part of Russia," said Alexander Boroday, the self-styled prime minister of the republic, referring to a wider eastern Ukrainian region containing heavy industry, coalmining and steel works.

Further away from the city center, rebels built up two new barricades overnight: by the sprawling residence of multi-billionaire Rinat Akhmetov, the country's richest man, and by the headquarters of the heavily armed, pro-Russian Battalion Vostok militia.

At a cemetery in the adjacent town of Makievka, 10 rebels fired into the air to honor their commrade, Vasily Burov, 46, killed on Thursday in a firefight with the Ukrainian army. (Writing by Sabina Zawadzki; editing by Stephen Addison)