 Complete the following phrase:  In June 1948, an armed insurgency by communist groups in Malaya broke out, and the British imposed harsh measures to control left-wing groups in both Singapore and Malaya; the controversial Internal Security Act, which allowed indefinite detention without trial for persons suspected of being threats to security, was enacted in Singapore at this time. Since the left-wing groups were the strongest critics of the colonial system, progress on self-government stalled for several years. The colonial government also tried to prevent contact between Singaporean Chinese and the Peoples Republic of China, which was 