Rescuers in Pakistan pulled five of seven children to safety after they became stranded with their teacher in a cable car high over a ravine, but a helicopter rescue operation was called off as night fell.

The sun was setting about 7pm as the first of the group were pulled from the cable car which broke as they were commuting to a school about 7am on Tuesday. 

It left those in is suspended 275 metres above the ground in remote Khyber Pakhtunkhwa province where cable cars are frequently used to connect remote villages and towns.

The first two children were rescued by helicopter, one by one, district official Shah Fahad and the military's media said.

Television footage showed one child being lifted off the cable car by a helicopter in a harness, swinging side to side before being carried to the ground.

Flood lights were installed on the ground and the rescue operation then continued without the aid of helicopters.

Cable crossing experts had been sent by the military to the remote area north of Islamabad and were trying to rescue the children one by one by transferring them on to a small platform along the cable.

"It is a slow and risky operation. One person needs to tie himself with a rope and he will go in a small chairlift and rescue them one by one," said Abdul Nasir Khan, a resident.

After nightfall three more children were rescued, Pakistan's military said.

"Three more children have been rescued in Pakistan army's rescue operation," the military said.

"Five children have been rescued so far. Operation is continuing."

Headmaster Ali Asghar Khan told AFP by phone that the children were teenage boys and students at his government high school Battangi Pashto.

A video shared by a rescue agency official showed more than a dozen rescuers and locals lined up near the edge of the dark ravine, pulling on a cable until a boy attached to it by a harness reached the hillside safely to cries of "God is great".

Residents said community members from surrounding areas who had experience rescuing people this way had also arrived.

The rescue operation struggled early as two initial attempts at helicopter rescue had to be aborted by 6pmdue to gusty winds and the danger posed by the helicopter's blade further destabilising the cable car.

A cable about nine metres above the car was also impeding efforts. 

Commandos managed to deliver food, water and "medicines to normalise heart rate" to the group in the afternoon. 

Pakistan Tourism described the ordeal on X, formerly known as Twitter, as Pakistan's most complex and sensitive rescue operation. 

"For God's sake help us," Gulfraz, a man stuck in the cable car, had told Pakistan television channel Geo News by phone.

"...The situation is so bad that one man has already fainted.

"A helicopter arrived, but left without conducting any operations."

Residents used mosque loudspeakers to alert neighbourhood officials across the valley.

At the scene, crowds of villagers gathered on the vertiginous hillside anxiously watching the operation.

ABC/Wires