A giant Antonov cargo plane crashed during a training exercise in central Russia, leaving all 12 military pilots aboard the aircraft missing and presumed dead, officials said on Wednesday.

Photo illustration of Russian pilots boarding an Antonov cargo plane.

The An-22 military plane carrying the servicemen but no cargo had been performing a training exercise on its way from Voronezh to Tver in central Russia when it disappeared from radar screens late Tuesday, said a spokeswoman for military prosecutors of the Moscow military district.

Its scattered remains were found early Wednesday in a field four kilometres from the village of Troitskoye in the Tula region, with the impact of the crash leaving a five-metre-deep crater in the ground, spokeswoman Natalya Zemskova told AFP.

"All those aboard died," the Moscow-based investigators said in a separate statement, adding local witnesses heard an explosion.

Zemskova said however that the pilots were presumed dead because officials were still looking for their bodies.

Igor Konashenkov, spokesman for the defence minister, said bad weather at the scene was hampering search efforts. "It\'s a blizzard and snowing," he said in televised remarks.

Dating back to the Soviet era, Antonov An-22 is a military cargo turboprop plane and is among the world\'s largest aircraft.

Authorities opened a criminal probe into the accident, said Zemskova, adding however it was too early to say what caused the crash.

Accidents involving military aircraft are relatively common in Russia.

Last year, another Russian military plane, a Tupolev Tu-142, crashed into the sea during a training exercise in Russia\'s Far East, leaving all 11 crew members missing and presumed dead.