GRENOBLE, France (AFP) - Some 33 tourists, including a 10-year-old child, spent the night stuck in cable cars thousands of metres up among the glaciers of Mont Blanc ahead of an expected rescue operation on Friday (Sept 9) morning, officials said.

The cable cars got stuck at 3.40pm local time on Thursday at an altitude of 3,800m in the French Alps after an unexplained technical incident, initially with 110 people on board.

Seventy-seven people were evacuated, including 48 who were airlifted out by helicopter and around 30 travelling in cars closest to the ground who were able to climb down with the help of rescuers.

The remaining tourists were forced to spend the night dangling in mid-air at high altitude and in deteriorating weather conditions after the rescue operation was suspended.

The prefect of the Haute-Savoie region, Mr Georges François Leclerc, said the rescue mission would recommence at 6.30am on Friday if weather conditions allowed.

"We were forced to stop rescue operations at 8:45pm" for safety reasons, the dark and the weather making it too dangerous, he said, adding that they were not able to "guarantee the safety of the pilots, rescuers and the people stuck in the cars".

"We hope to be able to evacuate everyone (Friday) morning first thing. We have done all we possibly could" this evening, he added, describing the mission as "very complicated".

Twelve people were later evacuated by Italian rescuers, he told AFP.

During the night, a team of five rescuers, three French and two Italian police officers also attempted to reach the trapped tourists. One of the officers managed to get into a car that contained a 10-year-old child.

Those still stuck have access to emergency blankets, energy bars and bottles of water in the cars.

The incident was caused by cables that got crossed for "unknown reasons", but a gust of wind is thought to have played a part, Mr Mathieu Dechavanne, chief executive of the Mont-Blanc Company that manages the cable cars, told AFP.

The employees of the company were not able to repair the cars, forcing an evacuation operation to begin around 5m.

The cable cars connect Aiguille du Midi on the French side of the mountains with Pointe Helbronner on the Italian border, where the rescued passengers were taken.

Weather conditions were at first good but later deteriorated turning cloudy at the high altitudes.

"The last hour was very, very long. We called the (Mont-Blanc) company, who explained to us that three cables had become tangled and there was only one left to un-cross but they weren't able to do it," a tourist told local radio station France Bleu Pays de Savoie.

"They tried to evacuate us but it was very difficult. I had to close my eyes for a good while and try to think about something else," he added.

The rescue operation involved four helicopters from France and Italy.

The cable cars, which carry four passengers each, offer panoramic views of Mont Blanc, which straddles the French-Italian border.

The incident comes five years after around 40 people were stuck for nearly seven hours on the Grande-Motte cable car in the south-eastern French Alps after it broke down. They were evacuated through trap doors in the floor of the cars, using ropes to reach the ground 40m below.