Prime Minister David Cameron said the crash of Malaysia Airlines Flight MH17 in Ukraine was "an absolutely appalling, shocking, horrific incident" and said his thoughts were with the families of those killed.
He said it was vital that the international community get to the bottom of what happened:
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."
Thousands of online users have taken to social media to call for the victims of the Malaysian airliner crash to be returned to loved ones.
United States intelligence officials admitted that they do not know who fired the surface-to-air missile that downed flight MH17.
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