the South against the wishes of North Yemen. The city became the State of Aden and the Federation was renamed the Federation of South Arabia (FSA). An insurgency against British administration known as the Aden Emergency began with a grenade attack by the communist National Liberation Front (NLF), against the British High Commissioner on 10 December 1963, killing one person and injuring fifty, and a "state of emergency" was declared. In 1964, Britain announced its intention to grant independence to the FSA in 1968, but that the British military would remain in Aden. The security situation deteriorated as NLF and FLOSY (Front for the Liberation of Occupied South Yemen) vied for the upper hand. In January 1967, there were mass riots between the NLF and their rival FLOSY supporters in the old Arab quarter of Aden town. This conflict continued until mid February, despite the intervention of British troops. On 20 June 1967, 23 British Army soldiers were ambushed and shot dead by members of Aden Police during the Aden Mutiny in the Crater District. During the period there were as many attacks on the British troops by both sides as against each other culminating in the destruction of an Aden Airways DC3 plane in the air with no survivors. The increased violence was a determining factor in the British ensuring all families were evacuated more quickly than initially intended, as recorded in From Barren Rocks to Living Stones. On 30 November 1967, British troops were evacuated, leaving Aden and the rest of the FSA under NLF control. The Royal Marines, who had been the first British troops to arrive in Aden in 1839, were the last to leave – with the exception of a Royal Engineer detachment (10 Airfields Squadron left Aden on 13 December 1967). Independence from the UK Aden ceased to be a Colony of the United Kingdom and became the capital of a new state known as the People's Republic of South Yemen which, in 1970, was renamed the People's Democratic Republic of Yemen. With the unification of northern and southern Yemen in 1990, Aden was no longer a national capital but remained the capital of Aden Governorate which covered an area similar to that of the Aden Colony. On 29 December 1992, Al Qaeda conducted its first known terrorist attack in Aden, bombing the Gold Mohur Hotel, where US servicemen were known to have been