A Malaysian Airlines B777-200 has been shot down on the Russian-Ukraine border, killing all 295 people on board, according to a Ukrainian interior ministry official.
Flight MH17, which was carrying 280 passengers and 15 crew, was flying between Amsterdam and Kuala Lumpur after taking off at lunchtime today.
The news agency reported that the aircraft went missing near Donetsk, where pro-Russian rebels have been fighting Ukrainian government forces.
TV pictures from the scene showed a pall of smoke billowing into the sky apparently from the stricken aircraft.
Witnesses say body parts are scattered over a distance of 15km, suggesting the plane broke up in mid-air.
It is believed the plane was struck by BUK surface-to-air missile at 33,000ft around 20 miles before entering Russian airspace.
The missile system is an old Soviet-built weapon designed to engage light aircraft, cruise missiles and drones.
Defence experts have expressed fears in the past they could be used to target at civil aircraft.
A similar launcher was seen by Associated Press journalists near the eastern Ukrainian town of Snizhne earlier today.
Malaysian Airlines said they have no information about any survivors.
In a tweet, the airline said: ‘Malaysia Airlines has lost contact of MH17 from Amsterdam. The last known position was over Ukrainian airspace.
A Boeing spokesman said: ‘Our thoughts and prayers are with those on board the Malaysia Airlines airplane lost over Ukrainian airspace, as well as their families and loved ones.
‘Boeing stands ready to provide whatever assistance is requested by authorities.
The jet would have been flying at high altitude on an intercontinental flight that took it over the crisis hit region of Ukraine, where the authorities have accused Russia-backed separatists of previous attacks on aircraft.
U.S. President Barack Obama has been briefed on the ongoing investigation.
Earlier today the Ukrainian authorities said one of their fighter jets was shot down by an air-to-air missile from a Russian plane and Ukrainian troops were fired upon by missiles from a village inside Russia.