A chartered plane carrying eight people, including Afghanistan's Mines and Industries Minister Juma Mohammed Mohammadi, hurtled into the Arabian Sea shortly after takeoff from Karachi on Monday, official sources said.
The Cessna aircraft, which was flying to Jazak near the Iranian border with Baluchistan, went down near Cape Mount off the coast of Karachi, killing all on board, they said.
The cause of the crash was not yet known but officials did not rule out sabotage.
The plane was chartered for going to a site in connection with the establishment of the $3.5 billion gas pipeline project from Turkmenistan across Afghanistan into Pakistan. The three countries have decided to invite India to join the venture.
On February 21, a plane carrying Pakistan's air chief, Air Marshal Mushaf Ali Mir, his wife and 15 others crashed in Kohat in the North-West Frontier Province.