Before he retired as MI5's wartime Director General in May 1946, David Petrie offered an assessment of the threat of Jewish terrorism in Europe and a warning: "the red light is definitely showing". The alert was confirmed by his successor Sir Percy Sillitoe in August and September, when he designated the Irgun and Lehi as the possibly planning to assassinate prominent English figures outside the Middle East. MI5 considered Mandatory Palestine a priority within the British Empire and had Defence Security Officers (DSO) stationed within the Mandate, working with local criminal investigation departments (CID) as well as MI5's sister agency the Secret Intelligence Service (SIS), to collect intel on Jewish terrorist threats to Britain. Their sources warned that the Irgun and Lehi were targeting British personnel outside Mandatory Palestine. MI5 were obliged to take these threats seriously: on 22 July 1946, the Irgun bombed the King David Hotel, housing British government offices, in Jerusalem, killing 91. A low intensity guerilla war was being waged in Palestine, with sabotage of communication lines and attacks on British soldiers and mandatory policemen, 99 being killed for the period 1 October through to 18 November. While the Haganah decided at this time to suspend its role in sabotage operations, the Irgun and the Lehi extended their operations to Europe to strike at British diplomatic representatives.