International probe in MH17 Ukraine plane disaster looks for more on Buk missile launchers

A Ukrainian honor guard carry a coffin with the remains of a victim of Malaysia Airlines flight 17 which was brought down over conflict-torn eastern Ukraine on July 17, 2014, into an aircraft headed to the Netherlands, in the city airport of Kharkiv, Ukraine, Saturday, March 28, 2015. The plane was brought down by a surface-to-air missile last July over pro-Russian rebel-held territory in eastern Ukraine, killing all 298 passengers and crew on board. (AP Photo) (The Associated Press)

A Ukrainian honor guard lift a coffin with the remains of a victim of Malaysia Airlines flight 17 which was brought down over conflict-torn eastern Ukraine on July 17, 2014, to take it into an aircraft headed to the Netherlands, in the city airport of Kharkiv, Ukraine, Saturday, March 28, 2015. The plane was brought down by a surface-to-air missile last July over pro-Russian rebel-held territory in eastern Ukraine, killing all 298 passengers and crew on board. (AP Photo) (The Associated Press)

An international investigation into the Malaysia Airlines Flight 17 disaster is officially looking into a scenario that the plane was downed by a missile fired from conflict-ridden eastern Ukraine.

A Dutch judicial statement said Monday the international investigating team is looking for witnesses "that can tell more about the transport, crew and firing of a Buk missile system in the Donbass region."

The cause of the MH17 disaster last summer is a subject of major diplomatic disputes. Ukraine and Western governments say Russia-backed separatist fighters are responsible for downing the plane, while Russian state-run television has claimed Ukraine's air force was to blame. All 298 people aboard the Boeing 777 flying from Amsterdam to Kuala Lumpur were killed.

The Dutch statement said it was "too early to come to conclusions."