Four people were killed and two others were injured when a helicopter crashed in Russia's oil heartland of Siberia on Thursday, the Emergencies Ministry said. A ministry spokesman said, in a statement carried by Reuters, that it was not immediately clear why the Mi-8 helicopter came down near Nefteyugansk, base of leading oil producer Yuganskneftegaz, formerly owned by stricken oil major YUKOS but now in the hands of state company Rosneft. "There were six people on board," the spokesman said. "Four of them were killed and two injured." The Interfax news agency said the Mi-8, with three technical experts and three crew members, was performing a routine inspection of oil pipelines when it crashed. It quoted Rostransnadzor, a civil aviation watchdog, as saying the Mi-8 may have become entangled with a cargo load attached by a cable to another helicopter. Accidents involving Mi-8s have become increasingly frequent in recent years. Earlier on Thursday the engine of a military Mi-8 with 11 people on board failed during a flight in the far eastern Khabarovsk region, news agencies reported. The pilot managed to make an emergency landing but an airforce commander ordered the grounding of all military Mi-8s pending an investigation, they said. Experts blame most of the accidents on technical fatigue of the fleet of Mi-8 helicopters - an ageing workhorse of Russian aviation which has been in service for more than 40 years -- and poor pilot training. --SP 1129 Local Time 0829 GMT
