12 presumed dead in Russian military plane crashA giant Antonov cargo plane has crashed during a training exercise in central Russia, leaving all 12 military pilots aboard the aircraft missing and presumed dead, officials say.The Antonov 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 (local time), a spokeswoman for military prosecutors said.Spokeswoman Natalya Zemskova says the plane's 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."All those aboard died," Moscow-based investigators said in a separate statement, adding local witnesses heard an explosion.Ms Zemskova, however, says the pilots are presumed dead because officials are still looking for their bodies.Igor Konashenkov, a spokesman for the defence minister, says bad weather at the scene is hampering search efforts."It's a blizzard and snowing," he said.Dating back to the Soviet era, the Antonov An-22 is a military cargo turboprop plane and is among the world's largest aircraft.Ms Zemskova says authorities have opened a criminal probe into the accident, adding, however, it is too early to say what caused the crash.Accidents involving military aircraft are common in Russia.Last year, 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.