The rebellion broke out at 2:00 am on 8 December. Signals from Brunei to British Far East Headquarters reported rebel attacks on police stations, the Sultan’s Istana, the Prime Minister’s house and the power station, and that another rebel force was approaching the capital by water. Far East Headquarters ordered ALE YELLOW, which placed a force of two Gurkha infantry companies on 48 hours notice to move.
By five in the morning, TNKU controlled Pekan Besar. News came that a number of civil servants at Pekan Besar had managed to escape capture. Around an hour later at downtown, the Deputy Chief Minister was granted an audience by the Sultan. After the meeting, the Sultan made a radio declaration condemning TNKU, the armed wing of the Brunei People's Party, for treason.
Nine hours after ALE YELLOW, ALE RED was ordered and two companies of 1st Battalion, 2nd Gurkha Rifles, of 99th Infantry Brigade, moved to the RAF airfields at Changi and Seletar in Singapore to fly to Labuan Island in Brunei Bay. The Beverleys landed at about 10:00 pm and the Gurkhas advanced into Brunei. They fought a series of actions, suffering six casualties, two fatal. A small group of Gurkhas led by Captain Digby Willoughby rescued the Sultan and took him to police headquarters. An advance to Seria met strong opposition and returned to Brunei to counter a rebel threat to its centre and the airfield.