The armed conflict escalated during the final phase of World War II, when the Irgun declared a revolt in February 1944, ending the hiatus in operations it had begun in 1940. Starting from the assassination of Baron Moyne by Lehi in 1944, the Haganah actively opposed the Irgun and Lehi, in a period of inter-Jewish fighting known as the Hunting Season, effectively halting the insurrection. However, in autumn 1945, following the end of World War II in both Europe (April–May 1945) and Asia (September, 1945), when it became clear that the British would not permit significant Jewish immigration and had no intention of immediately establishing a Jewish state, the Haganah began a period of co-operation with the other two underground organisations. They jointly formed the Jewish Resistance Movement. The Haganah refrained from direct confrontation with British forces, and concentrated its efforts on attacking British immigration control, while Irgun and Lehi attacked military and police targets. The Resistance Movement dissolved amidst recriminations in July 1946, following the King David Hotel bombing. The Irgun and Lehi started acting independently, while the main underground militia, Haganah, continued acting mainly in supporting Jewish immigration. The Haganah again briefly worked to suppress Irgun and Lehi operations, due to the presence of a United Nations investigative committee in Palestine. After the UN Partition Plan resolution was passed on 29 November 1947, the civil war between Palestinian Jews and Arabs eclipsed the previous tensions of both with the British. However, British and Zionist forces continued to clash throughout the period of the civil war up to the termination of the British Mandate for Palestine and the Israeli Declaration of Independence on 14 May 1948.