Shortly before the outbreak of World War II in Asia, the British detained several influential KMM leaders. However, most of them were freed during World War II, when the Japanese invaded and occupied Malaya. The former KMM leaders then formed "Kesatuan Rakyat Indonesia Semenanjung" (KRIS) to carry on KMM's work. However, the planned Greater Indonesia never materialised due to the sudden Japanese surrender after the bombing of Hiroshima and Nagasaki. With the return of the British, the KRIS leaders formed the Malay Nationalist Party (MNP; also known as the Persatuan Kebangsaan Melayu Malaya or PKMM) to achieve their goals through democratic means. However, the MNP was soon banned by the government as part of a crack-down on left-wing parties, ending the early phase of Malay nationalism.