LONDON (Reuters) - Britain wants a transparent investigation into the deadly crash of a Ukrainian airliner in Iran, Prime Minister Boris Johnson’s spokesman said on Thursday following a call between the British leader and Ukraine President Volodymyr Zelenskiy

“The prime minister said that there needed to be a full credible and transparent investigation into what happened,” the spokesman said.

Asked about reports on the causes of the crash, some of which have mooted a missile strike or terrorism, the spokesman said: “I’m not going to speculate on this, but reports we have seen are very concerning.”