By the spring of 1978, Mohammad Daoud Khan had alienated most key political groups by gathering power into his own hands and refusing to tolerate dissent. Although Muslim fundamentalists had been the object of repression as early as 1974, their numbers had nonetheless increased. Most ominous for Daoud, however, were developments among Afghan communists. Although plans for a Marxist coup had long been discussed, according to a statement by Hafizullah Amin, the April 1978 coup was implemented about two years ahead of time.
The April 19, 1978, funeral for Mir Akbar Khyber, a prominent Parchami faction ideologue who had been murdered, served as a rallying point for Afghan communists. An estimated 10,000 to 30,000 persons gathered to hear stirring speeches by Taraki and Karmal. Shocked by this demonstration of communist unity, Daoud ordered the arrest of People's Democratic Party of Afghanistan (PDPA) leaders, but he reacted too slowly. It took him a week to arrest Taraki, and Amin was merely placed under house arrest. According to later PDPA writings, Amin sent complete orders for the coup from his home while it was under armed guard using his family as messengers. The army had been put on alert on April 26 because of a presumed "anti-Islamic" coup. Given Daoud's repressive and suspicious mood, officers known to have differed with Daoud, even those without PDPA ties or with only tenuous connections to the communists, moved hastily to prevent their own downfall.
On April 27, 1978, a coup d'état beginning with troop movements at the military base at Kabul International Airport, gained ground slowly over the next twenty-four hours as rebels battled units loyal to Daoud in and around the capital. Daoud and most of his family were shot in the presidential palace the following day. Two hundred and thirty-one years of royal rule by Ahmad Shah and his descendants had ended, but it was less clear what kind of regime had succeeded them.
The ideologically divided PDPA succeeded the Daoud regime with a new government under the leadership of Nur Muhammad Taraki of the Khalq faction. In 1967 the PDPA had split into two groups -- Khalq and Parcham--but ten years later, the efforts of the Soviet Union had brought the factions back together, however unstable the merger. After March 1977, despite the fragile agreement on reunification, the Parcham and Khalq factions remained mutually suspicious.
In Kabul, the initial cabinet appeared to be carefully constructed to alternate ranking positions between Khalqis and Parchamis: Taraki was prime minister, Karmal was senior deputy prime minister, and Hafizullah Amin of Khalq was foreign minister. In early July, however, the Khalqi purge of Parchamis began with Karmal dispatched to Czechoslovakia as ambassador (along with others shipped out of the country). Amin appeared to be the principal beneficiary of this strategy, since he now ranked second, behind Taraki. The regime also issued a series of decrees, many of which were viewed by conservatives as opposing Islam, including one declaring the equality of the sexes. Land reform was decreed, as was a prohibition on usury. Between 8,000 and 12,000 opponents were ruthlessly killed.