UK & World News
Malaysia Plane: What Weapon Brought It Down?
Flight MH17 was a Boeing 777-200 travelling at an altitude of 6.2 miles (10km) when it was shot down near the village of Grabovo.
What sort of weapon could bring it down?
An advisor to the Ukrainian government says it was a missile launched from a Buk SA-11, a Russian surface-to-air missile system used by both the Russian and Ukrainian militaries.
US intelligence has confirmed a missile strike.
There have been recent reports that there are SA-11 in the region. Justin Bronk, from the Royal United Services Institute, a defence think tank, told Sky News the SA-11 would be the most likely weapons system.
The SA-11 is a tracked-vehicle with four missiles on top that can fire missiles up to 22,000 metres in the air, at a range of 20 miles (32km).
Ukrainian separatists have used man-portable air systems - shoulder launched missiles that use infrared but have a limited maximum altitude, well below MH17's cruising altitude.
The SA-11's radar can scan 360 degrees. When its crew detected MH17 at around 53 miles (85km) away they would have had between five and 10 minutes to acquire the plane, fire a missile and relocate.
The Buk uses radar, not infrared. It would be difficult to mistake a fighter jet for a passenger plane. But military transports - which have been targeted recently - do look similar.
The crew might have been aiming for a different plane in the area, and locked on to the MH17 by mistake, or locked onto MH17 believing it to be a transport.
Once the missile was fired, the crew would relocate immediately, as the powerful radar would give away their position.
Some airliners flying in conflict zones have missile warning alerts. Cruising along at what they thought was a safe altitude - even over a dangerous area of Ukraine - MH17 likely did not.
The pilots and crew would probably have had no indication a missile was coming.
The missile would not have flown directly into the jet, but drawn up close beneath it, then detonated.
However, engineer Daniel Holland told Sky News the wreckage looks more consistent with a missile impact to the tail or wing, given the spread of debris.
The Pentagon has satellites looking down over Ukraine. They will now be looking for the flash of the launch - and the radar signature of the Buk, which is highly unusual for the region.