Gunfire, airstrikes leave Donetsk Intl airport up in smoke (PHOTOS, VIDEO)

Donetsk self-defense forces claim on Twitter to have regained control over the international airport in the eastern city after Ukrainian troops launched a military operation there, deploying fighter jets and helicopters.

“The people’s army has the airport in Donetsk back under control. We are rooting out the remaining Kiev’s remaining troops. Airstrikes have stopped for now,” said the tweet from the self-proclaimed People’s Republic of Donetsk.

However, other reports on Twitter suggest shooting in Donetsk still goes on, now moving to the downtown.

More loud explosions - several different types - audible in city centre #Donetsk & what sounds like a fighter jet #Ukraine

— Harriet Salem (@HarrietSalem) May 26, 2014

Earlier, RT’s Maria Finoshina reported from Donetsk that Ukrainian fighter jets and helicopters were again unleashed at the armed self-defense occupying the airport. The second stage of Kiev's "counter-terror operation" came amid reported negotiations between rebels and the Ukrainian forces at the scene.

“The Ukrainian occupiers are conducting missile and bomb strikes on Donetsk International Airport. They are deploying military aircraft,” self-defense forces said on Twitter amid the intense fighting.

"I have heard at least three blasts. Helicopters are circling over the city and military jets can be heard flying by," witnesses told local daily Ostrov.

Loud explosions and gunfire were reported from Donetsk throughout the day, with Ukrainian army aircraft occasionally circling around the airport. A missile launched in one of the air raids reportedly hit the nearby Tochmash machinery plant, injuring at least one person, according to ITAR-TASS.

Just saw a man accidentally killed by incoming fire by the central train station #Donetsk. The station building is damaged

— Petr Shelomovskiy (@shelomovskiy) May 26, 2014

Moscow has filed an urgent request with the OSCE, asking that the organization and its monitors working in Ukraine present a thorough report on the situation in Donetsk and explain what measures on de-escalation of the conflict are being taken in accordance with the OSCE roadmap.

“We await objective and thorough data from the OSCE representatives and demand the Kiev authorities to stop the military operation against their own people,” the Russian Foreign Ministry said in a statement.

Shooting, fire at Donetsk railway station results in casualties

Reports of fighting outside the city airport have also emerged. RT’s sources in Donetsk said a private housing area was being shelled by mortar fire “for over an hour.”

At the Donetsk central railway station a fire broke out and gunfire was heard, the area evacuated. One civilian was killed and two, including an 8-year-old boy, sustained injuries in the shooting, the region's administration told RIA Novosti.

Ukrainian warplane & helicopter attack leaves Donetsk Intl Airport smoking http://t.co/u30HD6H57Jpic.twitter.com/FViCtwBua1

— RT (@RT_com) May 26, 2014

An ANNA News reporter streaming a live broadcast from the airport area came under helicopter fire together with local and foreign journalists. According to the streamer, fortunately, only one female journalist suffered mild shock.

Su-25 military jets, MiG-29 helicopters dispatched to airport

“The counter-terror operation started as two Sukhoi Su-25s flew to the airport. They made a warning shot to the area of the terrorists’ location,” Aleksey Dmitrashkovsky, from the SBU press service told the portal. As the self-defense forces fired back, two military choppers, a MiG-29 and Mi-24, were deployed which say the rebels’ forces scattered across the airport.

“Paramilitary troops arrived and they are now cleaning the area off,” Dmitrashkovsky said adding he has no information on casualties.

Airstrikes started after the self-defense forces failed to comply with the ultimatum put forward by Kiev's troops, that is to surrender by 13pm local time, Vladislav Seleznyov, the head of the counter-terror operation, said on his Facebook page.

The airport, which serves Donetsk, Kharkov, Lugansk and Zaporozhie regions, has been closed “for security reasons”, and Reuters witnesses are seeing smoke billowing from the building. Kiev’s authorities had demanded civilians are evacuated from the airport terminal’s vicinity and the landing field, locals told RT adding that mobile connection was also down at some point.

Early on Monday morning, forces belonging to the self-proclaimed Donetsk People's Republic came to the airport demanding that Ukrainian troops leave it. The self-defense troops said some 200 Kiev soldiers were guarding the inner perimeter of the hub.

The airport was forced to suspend flights. The airport’s press secretary Dmitry Kosinov told RIA Novosti news agency that “operations will be resumed when armed people leave the terminal.”

The State Aviation Service halted the air traffic through the airport till 9.00am local time Tuesday.

The clashes in Donetsk began just a few hours after the early results of the elections were announced.

Billionaire Petro Poroshenko is currently leading in the Ukrainian presidential election. He is in favor of continuing the military operation in the southeast of the country.

“I don’t have the information, denoting that it [the operation] must now be stopped,” Poroshenko said at a news conference. "I support its continuation, but demand a change in its format – it must be shorter and it must be more effective, military units must be better equipped.”

URGENT: 2 reported injured as Ukrainian troops resume airstrikes on #Donetsk Airport - report http://t.co/u30HD6H57Jpic.twitter.com/FaDzbwnQ7c

— RT (@RT_com) May 26, 2014