Kathmandu, Mar 3: At least 10 persons were killed when a United Nations helicopter crashed in Eastern Nepal's mountainous Sindhuli district on Monday, airport authorities said. "So far, 10 bodies have been recovered from the debris of the chopper, which is believed to have been carrying 11-15 people," Mohan Adhikari, Airport Manager at the Tribhuvan International Airport said. Preliminary investigation revealed that the helicopter was struck by a lightening as it was flying amid heavy rain. "The helicopter was going from Northern Cantonment in Sindhuli to Kathmandu when the accident occurred in Dhudhauli in the same district," he said. Locals saw a huge explosion when the chopper crashed. The helicopter had lost contact with the airport and crashed soon after it had taken off, he said. The United Nations was also expected to release a statement on the mishap soon. In 2006, 24 people including senior government officials and diplomats died in a helicopter crash caused by adverse weather in east Nepal.