 The COBRA meetings continued through the night and into Thursday . Meanwhile , two teams were dispatched from the headquarters of the Special Air Service ( SAS ) near Hereford , and arrived at a holding area in Regent 's Park Barracks . The teams — from B Squadron , complemented by specialists from other squadrons — were equipped with CS gas , stun grenades , and explosives and armed with Browning Hi @-@ Power pistols and Heckler & Koch MP5 submachine guns . Lieutenant Colonel Michael Rose , commander of 22 SAS had travelled ahead of the detachment and introduced himself to Dellow , the commander of the police operation . At approximately 03 : 30 on 1 May , one of the SAS teams moved into the building next door to the embassy , normally occupied by the Royal College of General Practitioners , where they were briefed on Rose 's " immediate action " plan — to be implemented should the SAS be required to storm the building before a more sophisticated plan could be formed . 
