Emergency workers on Sunday finished combing the debris-laden runway of an airport in southern Russia where a plane carrying 62 people crashed before dawn on Saturday.

FlyDubai's Boeing 737-800 from Dubai nose-dived and exploded in a giant fireball after trying to land for a second time in strong winds in the Russian city of Rostov-on-Don.

FlyDubai confirmed there were no survivors among the 62 passenger and crew and said four children were among those killed. Most of the passengers were Russian.

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Investigators have finished combing the area of the crash site, but say it could take up to a month to decode the badly damaged black boxes that were retrieved. (AFP/Getty Images)

Several planes had trouble landing at the airport at the time of the crash, with one trying to land three times before giving up and diverting to another airport, experts said.

Hundreds of people flocked Sunday to the airport, the region's largest, to lay flowers and leave candles and toys in memory of the dead. The city is 950 kilometres south of Moscow near the Ukrainian border.

State-owned Rossiya-24 on Sunday interviewed a mourner living nearby who said she was woken up by the sound of the explosion.

"The housed started shaking. I looked out of the window: the sky was red and in a few seconds it was over," said the woman, whom Rossiya did not identify.

Closed-circuit TV footage showed the plane going down at a steep angle and exploding. The powerful explosion left a big crater in the runway and pulverized the plane.

Examining black boxes

Emergency Situations Minister Vladimir Puchkov said Sunday that the plane's two black boxes — its cockpit voice and flight data recorders — have been taken to Moscow for examination. They will be viewed by experts from Russia, the United Arab Emirates, France and the U.S., since the American-made Boeing plane had French-made engines.

Rostov-on-Don, Russia

FlyDubai has been flying to Rostov-on-Don, about 950 kilometres south of Moscow, since 2013.

NBC quotes officials at Russia's airline regulator as saying both black boxes were badly damaged in the crash and that it could take up to a month to decode them.

Transport Minister Maxim Sokolov told reporters that emergency teams had finished combing the area and that authorities were now waiting for investigators to give the green light to let repair teams ont the runway. Sokolov said he expects the airport to open early Monday.