LONDON (Reuters) - British Prime Minister Boris Johnson said on Thursday there was a body of evidence that a Ukrainian airliner that crashed in Iran was downed by a surface to air missile that might well have been fired unintentionally.

Echoing the conclusion of the United States and Canada, Johnson called for a full and transparent investigation into the crash which killed all 176 people on board including four Britons.

“There is now a body of information that the flight was shot down by an Iranian Surface to Air Missile. This may well have been unintentional,” Johnson said in a statement. “The UK continues to call on all sides urgently to deescalate to reduce tensions in the region.”