David Cameron vowed that those responsible for the Flight MH17 disaster would be tracked down as he held talks with world leaders on the international community’s response to the crisis.
The Prime Minister chaired a meeting of Cobra, Whitehall’s emergency committee, and ordered British air accident investigators to head to the crash site in Ukraine.
Police disaster experts from this country will also help the Dutch authorities to repatriate the bodies of passengers killed on Thursday. Ten Britons are now believed to have been killed.
Mr Cameron spoke of his outrage over the atrocity, but stopped short of blaming pro-Russia separatists for bringing down the Malaysia Airlines aircraft.
“It is an absolutely shocking incident. It cannot be allowed to stand,” he said. “If, as seems possible, this was brought down, then those responsible must be held to account and we must lose no time in doing that.”
Downing Street tonight said the Government believed it was “increasingly likely” the aircraft has been shot down by pro-Russian separatists.
A spokeswoman said: “The growing weight of evidence suggests that MH17 was shot down by a surface to air missile and that this was fired from near Torez, in territory controlled by the separatists. “This is backed up by claims made by separatist leaders on social media, and later removed, to have shot down an aircraft that they thought belonged to the Ukrainian military.
“On this basis we assess that, without compelling information to the contrary, it is increasingly likely that MH17 was shot down by a separatist missile.”
Earlier, UK officials said the priority had to be for international investigators to establish the cause of the crash and to be able to carry out their work without interference from separatist forces controlling the area.
A Downing Street spokeswoman challenged the Russian President, Vladimir Putin, who has supported an investigation, to back his words with action.
“President Putin has said on this there should be an investigation. That is why we said very clearly that people should do all they can to enable that to happen – not just words,” she said.
Britain led the call for today’s emergency meeting of the United Nations Security Council.