US search and rescue crews have used ropes and helicopters to rescue 21 people who were stranded overnight in two cable cars in New Mexico.

Passengers in the cable cars were stuck high up in the Sandia Mountains overlooking Albuquerque.

Robert Arguelles, a Bernalillo County Fire Department spokesperson, said that crews rescued 20 people stranded in one car and, several hours later, rescued a 21st person stranded on their own in a second car.

All the people were employees of the Sandia Peak Aerial Tramway or a mountaintop restaurant, and the 20 in one car were being ferried down to the base of the mountains at the end of their working days, Mr Arguelles said.

The other employee had been heading up the mountain to provide overnight security when the tram system shut down on Friday night due to icing, Mr Arguelles said.

There were no reported injuries among those stranded, he said. “More just pretty frustrated.”

To rescue the 20 people in one car, operators were able to move it to a nearby support tower more than halfway up the mountain, and search and rescue personnel hiked to the area and climbed the tower to deliver blankets and other supplies to those inside the heated car, Mr Arguelles said.

Search and rescue personnel over several hours used ropes and other equipment to lower the stranded employees about 85ft to the ground before escorting them to a nearby landing zone in the steep and rocky terrain where the tower was located.

The 20 people were then ferried by helicopter several at a time to the base of the mountains, he said.

The second car with the one employee aboard was higher up the mountain and at a location where the car was too high above the ground to lower people by ropes.

But the tram system was able to inch the second car down the cable to the rescue site at the support tower, and rescuers then used ropes to lower the 21st person as was done with the others, Mr Arguelles said.

Brian Coon, a tramway system manager, said there was an unusually fast accumulation of ice on one of the cables that made it droop below the tram, making it dangerous to keep going, KOB-TV reported.