Actually this did happen - but in December 1999.
Pro Taliban hijackers took control of an Air India flight en-route from Kathmandu to Delhi and made the crew fly it to Kabul and subsequently Kandahar. One passenger was stabbed to death and several cabin crew wounded.
The indian government were forced to free several jailed islamic militants in order to secure the release of the passengers and crew. The hijackers simply vanished, although one of the gang is rumoured to have been among the team that flew into the World Trade Centre.