 At the same time, the members of FLOSY and the NLF were also killing each other in large numbers.The temporary closure of the Suez Canal in 1967 effectively negated the last reason that British had kept hold of the colonies in Yemen, and, in the face of uncontrollable violence, they began to withdraw.On 20 June 1967, there was a mutiny in the Federation of South Arabia Army, which also spread to the police.