a local non S-Plan-involved IRA unit. In Lancashire, an unexploded package of gelignite and a stopped alarm clock timer were found attached to an electricity pylon. Arrests were made, with a London man charged with possession of 2 tons of potassium chlorate and 1 ton of iron oxide between 1 October and 5 November 1938. 22 January – In Vauxhall an arrest was made in connection with the Southwark explosion. 23 January – In Manchester two women were arrested on possession of explosives. Items seized included one barrel of potassium chlorate, two Mills bombs, 49 sticks of gelignite, and 10 electric detonators. Sir Dawson Bates, then Northern Ireland Minister of Home Affairs, revealed the existence of an "execution list of NI officials" (which had been seized in Belfast) to the British press. February 4 February Two bombs exploded in the London Underground – one at Tottenham Court Road station and one at Leicester Square station. They were timed suitcase bombs stored in the left-luggage rooms overnight. There were no fatalities, although two people were seriously injured and severe damage was done to the facilities. This attack generated a good deal of panic and alarm amongst the British population. Questions were asked in the British Parliament about the IRA's 12 January ultimatum to the British government. The ultimatum had previously been publicised in the British newspapers following the 17 January attack. British Home Secretary Sir Samuel Hoare informed the House of Commons that the police had already arrested 33 people in connection with the attacks up to that point and that the security authorities were doing everything within their power to find the perpetrators. In Liverpool, an unsuccessful attempt was made to blow up one wall of Walton Gaol, but the wall was not penetrated. In London, fires broke out within half an hour of each other in shops in one of the suburbs. The British police established that in each case the fire was due to a chemical mixture which ignited when exposed to the air. Plans to blow up Buckingham Palace were reported by The Times to have been found in Belfast. As a result, night and day guards were placed around the grounds of Royal Lodge and Windsor Great Park. All visitors to the state apartments at Windsor Castle and St. George's Chapel were also reported to have been stopped and searched before being allowed entry. 5 February