The Buk missile system that Kiev suspects downed the Malaysia Airlines airliner over rebel-held territory with 298 people on board in July is a powerful and precise Russian weapon operated by countries such as North Korea and Syria.
The 700-kilogramme (1,500-pound) surface-to-air missile -- referred to as the SA-11 Gadfly by NATO -- requires highly trained specialists to operate that the West believes were smuggled into eastern Ukraine from Russia.
It works by exploding directly outside the target and hitting it with a massive amount of high-velocity shrapnel.
A preliminary report into the disaster released in the Netherlands on Monday concludes that the Boeing 777 "broke up in the air probably as the result of structural damage caused by a large number of high-energy objects that penetrated the aircraft from outside."
Russia has alleged that the aircraft was destroyed by the Ukrainian airforce as part of a Machiavellian plan to blame the downing on pro-Kremlin militias that controlled the area where the plane was hit.
But an air-to-air missile fired by a fighter jet hits the target directly and does not cause "a large number of high-energy objects that penetrated the aircraft from outside", the report said.
Ukraine has alleged that at least one Buk system was spotted being ferried into the area from Russia in the days preceding the incident.
Russia denies this and counters that separatist fighters did not possess such weapons and lacked the knowledge to make one work.
The London-based Jane's defence and intelligence agency says that up to six Buk missiles can be fired from a launcher vehicle -- usually either a military truck or a tank.
It locates and locks onto targets using a separate and highly sensitive radar system that is usually operated from an accompanying mobile unit.
The system can operate in any weather and reportedly hit some targets at an altitude of 25 kilometres (15 miles) or more.
The Boeing was flying at a cruising altitude of 33,000 feet (about 10 kilometres).