A Ukranian fighter jet tumbled to earth in a fireball Thursday after it was blasted out of the air while flying low over rebel-held territory in the east of the country.

An AFP crew saw the Sukhoi warplane explode in mid-air and the parachute of at least one pilot opening up in the clear blue sky.

Explosions and flashes erupted from the wreckage as it continued to burn on the ground, sending up clouds of acrid smoke.

Two armed rebels ran around the blackened field close to the flaming debris as the sound of shooting rang out nearby.

Another plane could be heard flying high overhead and the insurgents shouted at the AFP team to leave the scene.

A local resident told AFP that he had seen at least two parachutes appear after the aircraft was hit.

"It flew past us and there was an explosion. Two pilots ejected out," said Danil, 17.

A Ukrainian military spokesman confirmed that rebels had shot down a jet some 40 kilometres (25 miles) to the northeast of the rebel stronghold Donetsk.

"The pilot managed to steer the craft away from a residential area," spokesman Vladislav Seleznyov told AFP.

A search-and-rescue mission was currently underway for the pilot, he said.

The location was also some 40 kilometres west of the site where Malaysia Airlines flight MH17 was shot down at an altitude of some 10,000 metres on July 17 killing all 298 people on board.

The Ukrainian military has lost a string of aircraft during almost four months of fierce fighting against pro-Russian rebels in east Ukraine that has claimed over 1,300 lives.

Two Ukrainian Sukhoi jets were shot down on July 23, with Kiev alleging the missiles that hit them had come from Russian territory.

On Thursday the Ukrainian army announced it was scrapping a ceasefire around the MH17 crash site after international investigators decided to suspend their probe there due to ongoing fighting.

Sustained shelling pounded the centre of the rebel stronghold of Donetsk for the first time in the conflict, with at least 11 civilians killed by clashes around the region.