Under the temporary command of Hanoch Kalai, the Irgun began sabotaging strategic infrastructure such as electricity facilities, radio and telephone lines. It also started publicizing its activity and its goals. This was done in street announcements, newspapers, as well as the underground radio station Kol Zion HaLochemet. On August 26, 1939, the Irgun killed Ralph Cairns, a British police officer who, as head of the Jewish Department in the Palestine Police, had tortured a number of youths who were underground members. Cairns and Ronald Barker, another British police officer, were killed by an Irgun IED.