 As the deadline of noon approached, set the previous day for the release of the Arab prisoners, the police became convinced that the gunmen did not have the capability to carry out their threat of blowing up the embassy, and persuaded Oan to agree to a new deadline of 14: 00. The police allowed the deadline to pass, to no immediate response from the gunmen. During the afternoon, Oan altered his demands, requesting that the British media broadcast a statement of the group's grievances and for ambassadors of three Arab countries to negotiate the group's safe passage out of the UK once the statement had been broadcast. At approximately 20: 00, Oan became agitated by noises coming from the Ethiopian Embassy next door. The noise came from technicians who were drilling holes in the wall to implant listening devices, but PC Trevor Lock, when asked to identify the sound, attributed it to mice. COBRA decided to create ambient noise to cover the sound created by the technicians and instructed British Gas to commence drilling in an adjacent road, supposedly to repair a gas main. The drilling was aborted after it agitated the gunmen, and instead British Airports Authority, owner of London Heathrow Airport, was told to instruct approaching aircraft to fly over the embassy at low altitude.
