An in-flight fuel explosion probably caused Tuesday's crash of an ageing Antonov An-12 cargo aircraft in Russia's Far East, a law enforcement source in the Magadan Region said on Wednesday. All Russian An-12s were grounded on Wednesday whilst investigators try to determine the cause of the crash. The plane, flying from the city of Magadan to the Chukotka Autonomous Area in Russia's extreme northeast, was carrying 11 people and around 18 metric tons of cargo. It disappeared from radars some 300 km (186 miles) from its takeoff point shortly after reporting a fuel leak and engine fire. No survivors were found when rescuers reached the crash site in helicopters on Wednesday morning. The Emergencies Ministry reported that the flight recorders have been discovered and that debris from the plane was scattered across a radius of several kilometers. "This allows us to assume that an explosion occurred on board the aircraft as a result of a fuel leak," the source said. The crashed An-12 was the oldest in the Russian fleet, and had flown for 48 years.