The first event to signal the eventual overthrow of the Afghan government came on the night of July 17, 1973.
Something roared like thunder. The earth shook a little and we heard the rat-a-tat-tat of gunfire... A siren went off in the distance. Somewhere glass shattered and someone shouted.
It was the first night of the "bloodless coup" by Prince Mohammed Daoud Khan, who had overthrown the government of his cousin, King Zahir Shah, who was away in Italy. Rather than name himself Shah, Daoud instead made himself President of Afghanistan, and he declared the nation a democracy. Daoud allied himself with the Russians, who supplied Afghanistan with advanced weapons for years. In 1977, Daoud attempted to disassociate his nation with the USSR, angering Soviet officials. Daoud was assassinated on April 28, 1978, the day after a coup d'tat by Russian-backed Afghan rebels. The new rebel government announced that Daoud had resigned, but his body was eventually found in a mass grave near Kabul in June 2008.
According to Amir, the bombings started on the night of 17 July, 1973, when the soviets marched in Wazir Khan district.