A Bangladeshi-origin Briton who pledged allegiance to the Islamic State group has been found guilty of hatching a terror plot to behead Prime Minister Theresa May in a suicide attack on Downing Street.

Naa'imur Zakariyah Rahman, on trial at the Old Bailey court in London this week, planned to bomb the gates of 10 Downing Street, kill guards and then attack the prime minister with a knife or gun. His plan was foiled as a result of a joint undercover operation by the FBI in the US and MI5 and Scotland Yard in the UK.