They are refusing to leave Afghanistan - the fourth stop in a terrifying ordeal in which at least one passenger has been killed.
An airport official in the southern city of Kandahar said the gunmen had told ruling Taleban officials they would land in the capital, Kabul, if forced to leave the airport.
"We have already provided fuel to the plane and food but the hijackers have refused to go," said the official.
"If permission for landing in Kabul is not given, then we will crash the plane ... We won't leave Afghanistan," he quoted a hijacker as saying.
The aircraft - with more than 160 people still on board - has been flying between airports across the Indian sub-continent and Middle East since gunmen first took control of it on Friday.
It flew to Afghanistan from Dubai, where negotiators from the United Arab Emirates agreed to a refuelling request in return for the release of 25 passengers. Most of the freed hostages were women and children.
The body of one passenger, reportedly stabbed to death by a hijacker, was also removed from the plane.
The hijackers say there are four more bodies, those of two passengers and two crew, on the aircraft.
'Asylum refused'
Afghanistan's ruling Taleban authorities allowed the plane to land and refuel in Kandahar early on Saturday after a request from the Indian Civil Aviation Authority.
Taleban Foreign Minister Wakil Ahmed Muttawakil said: "The Indian authorities have been in touch with our embassy and asked that the plane be allowed to land in Kandahar. The pilot is very tired, they told us."
But the Taleban have condemned the hijackers as terrorists, and according to a Kandahar airport official, have turned down their request for political asylum.
The BBC's Kate Clark in Kabul says the gunmen are believed to be Sikhs and it is not clear why they would want to go to Afghanistan, which is controlled by the Islamic Taleban.
Troops from the fundamentalist regime surrounded the aircraft after it landed and prepared to provide fuel.
But they resisted Indian demands for a rescue and refused to let the hijackers leave the plane. The Indian Prime Minister Atal Bihari Vajpayee has refused to negotiate with the hijackers and is also refusing to celebrate his birthday during the crisis.
"This is a very cowardly act. India will never be cowed down by such barbaric acts," he told reporters in New Delhi.
So far, any demands the hijackers have made, apart from refuelling requests, have not been made public.
Popular route
There were originally about 190 people on board when armed gunmen took control of the plane, which was on a flight from Kathmandu to Delhi.
The drama began at about 1130 GMT on Friday with the hijackers demanding to be taken to Lahore, but landing permission was then denied by the Pakistan Government.
The plane touched down briefly at the Indian city of Amritsar before flying on to Lahore. It landed there without permission and despite the fact that runway lights had been switched off.
The plane was reported to be on the point of running out of fuel as it landed.
The decision to allow the plane to refuel and leave Lahore came after the hijackers claimed to have killed some of those on board.
The A300 Airbus was on a daily run between Kathmandu and Delhi - a popular route for tourists and business travellers.
There were originally reported to be 189 passengers on board, of whom 150 are Indian. Other nationalities include Nepali, Swiss, Spanish, Canadian, French, Belgian, American, Japanese and Italian.
In the past, attempts to hijack Indian aircraft and take them to Lahore have failed, usually because authorities there refused the aircraft permission to land.
The last such hijacking took place in 1993, when a lone hijacker commandeered an aircraft and attempted to take it to Pakistan.
The hijackings have usually been carried out by separatist militants.
An alliance of groups fighting Indian rule in the disputed territory of Kashmir, however, has denied involvement in the hijacking.
"None of the militant groups engaged in occupied Kashmir are linked with this plane hijack nor does our faith and our sacred struggle permit murder of any innocent person," a statement by the 14-group Muttahida Jihad Council said.