Six children and two teachers are trapped in chair lift hanging 274 metres (900 feet) above a ravine in Pakistan after a cable snapped, with a tricky helicopter rescue mission being hampered by high winds, rescue officials said on Tuesday.

The children, who have been stranded since 7 a.m local time (0200 GMT), were using the chair lift to get to school in a mountainous area in Battagram, about 200 kilometres (125 miles) north of Islamabad, officials said.

Pakistan's National Disaster Management Authority said in a statement that a cable had broken in the lift service and an army helicopter had been dispatched for a rescue operation after attempts at fixing the fault had been unsuccessful.

The open chair lift became stranded half way across a ravine and was hanging by a single cable after the other snapped, Shariq Riaz Khattak a rescue official at the site told Reuters.

The rescue mission is complicated due to gusty winds in the area and the fact the helicopter's rotor blades risk further destabilising the lift, he said.

One chopper has already conducted surveillance and then returned, and another one would be sent shortly, he added.

People who live in the northern mountainous regions of Pakistan often use chair lifts for transport from one village to another.

Pakistan's caretaker Prime Minister Anwaar-ul-Haq Kakar expressed concern in a post on messaging platform X, formerly known as Twitter.

"I have also directed the authorities to conduct safety inspections of all such private chair lifts and ensure that they are safe to operate and use," he said in a post.