After establishing a series of jungle bases the MNLA began raiding British colonial police and military installations. Tin mines and rubber plantations were attacked by communist guerrillas in an attempt to gain independence for Malaya by making the colonial occupation too expensive for the British to maintain. The British attempted to starve the communist guerrillas by implementing a food denial campaign which saw the enforcement of food rationing, the killing of livestock and aerial spraying of chemical herbicides to destroy rural farmland. Early in the conflict, British attempts to defeat the communists included extrajudicial killings of unarmed villagers, the most infamous case being the Batang Kali massacre, often referred to as "Britain's Mỹ Lai". Furthermore, the Briggs' Plan was enacted to imprison 500,000 people (or up to 10% of the Malayan population at the time) into internment camps called "New villages", despite violating the Geneva Conventions. Many Orang Asli indigenous communities were also targeted for internment because the British believed that they were supporting the communists.