Armed conflict between Tibetan rebels and the Chinese army (PLA) broke out in 1956 in the Kham and Amdo regions, which had been subjected to socialist reform. The guerrilla warfare later spread to other areas of Tibet. In March 1959 a revolt erupted in Lhasa, which had been under the effective control of the Communist Party of China since the Seventeen Point Agreement in 1951. On 12 March, protesters appeared in the streets of Lhasa declaring Tibet's independence. Within days, Tibetan troops prepared to secure an evacuation route for the Dalai Lama, who fled into exile during the uprising. Artillery shells landed near the Dalai Lama's Palace, prompting the full force of the Uprising. Combat lasted only about two days, with Tibetan rebel forces being badly outnumbered and poorly armed. Reprisals for the 1959 Tibetan uprising involved the killing of 87,000 Tibetans by the Chinese count, according to a Radio Lhasa broadcast of 1 October 1960, although Tibetan exiles claim that 430,000 died during the Uprising and the subsequent 15 years of guerrilla warfare, which continued until the US withdrew support. China suffered widespread famine between the years 1959 and 1961. The causes are disputed. Drought and poor weather played a part and the policies of the Great Leap Forward contributed to the famine, but the relative weights of each are in dispute. Estimates of deaths vary; according to official government statistics, there were 15 million deaths. Unofficial estimates by scholars have estimated the number of famine victims to be between 20 and 43 million. On May 1962, the Tenth Panchen Lama sent Chinese Premier Zhou Enlai a confidential report detailing the suffering of the Tibetan people, which became known as the 70,000 Character Petition. "In many parts of Tibet people have starved to death.. . . In some places, whole families have perished and the death rate is very high. This is very abnormal, horrible and grave...In the past Tibet lived in a dark barbaric feudalism but there was never such a shortage of food, especially after Buddhism had spread...In Tibet from 1959 to 1961, for two years almost all animal husbandry and farming stopped. The nomads have no grain to eat and the farmers have no meat, butter or salt," the report continued. It was the opinion of the Panchen Lama that these deaths were a result of official policies, not of any natural disasters, which was the situation understood in Beijing by Chairman Mao and the Central People's Government. The Panchen Lama also described the uniqueness of the famine that Tibet suffered from: "There was never such an event in the history of Tibet.