In 1978 a prominent member of the People's Democratic Party of Afghanistan (PDPA), Mir Akbar Khyber (or “Kaibar”), was killed by the government. The leaders of PDPA apparently feared that Daoud was planning to exterminate them all, especially since most of them were arrested by the government shortly after. Hafizullah Amin and a number of military wing officers of the PDPA managed to remain at large and organised an uprising.
Born in 1925, Khyber graduated from the military high school in 1947. In 1950, he was imprisoned for his revolutionary activities. Later he was employed by the Ministry of education, until he was expelled from Paktia for taking part in a riot in 1965. After returning to Kabul, he became editor of the Parcham newspaper, Parcham and oversaw the Parchams recruitment program in the Afghan army.
He was assassinated outside his home on 17 April, 1978. The Daoud regime attempted to put the blame for Kyber's death on Hekmatyar's Hezbi Islami, but Nur Mohammad Taraki of the PDPA charged that the government itself was responsible, a belief that was shared by much of the Kabul intelligentsia. Louis Dupree, an American historian and specialist of Afghanistan, concluded that interior minister Nuristani, a virulent anti-communist, had ordered the killing. However, several sources, including fellow parchamis Babrak Karmal and Anahita Ratebzad, claim that Hafizullah Amin, a leader of the rival Khalq faction, was the instigator of the assassination. Daoud's confidant, Abdul Samad Ghaus, suggested that a strong rivalry existed between Amin and Khyber as they both attempted to infiltrate the military for their respective factions. Also, Khyber's attempts to reunite Khalq and Parcham cells within the military would have undermined Amin's power, according to communist sources.
At Khyber's funeral on April 19, some 15, 000 PDPA sympathizers gathered in Kabul, and paraded through the streets chanting slogans against the CIA and the SAVAK, the Shah of Iran's secret police. Alarmed by this demonstration of communist strength, Daoud ordered a crackdown on the PDPA leadership, which in turn prompted the PDPA to launch a military coup that became known as the Saur Revolution, during which Daoud was killed, and the PDPA took power.