Most of the victims died of hypothermia, officials said. Among them was an Islamabad police officer and seven other members of his family, fellow police officer Atiq Ahmed said.

More than 4 feet (1 metre) of snow fell in the area of the Murree Hills resort overnight Friday and early Saturday, trapping thousands of cars on roadways, said Interior Minister Sheikh Rashid Ahmed.

The snow was so severe that heavy equipment brought in to clear it initially got stuck during the night, said Umar Maqbool, assistant commissioner for the town of Murree.

Temperatures fell to minus 8 degrees Celsius (17.6 degrees Fahrenheit).

Officials called in paramilitary troops and a special military mountain unit to help. By late Saturday, thousands of vehicles had been pulled from the snow but more than a thousand were still stuck, Ahmed said.

Rescue 1122, Pakistan’s emergency service, released a list naming 21 people it said had been confirmed dead.

Rescue services physician Abdur Rehman put the toll at 22, including 10 men, 10 children and two women.

Emergency officials distributed food and blankets to people while they were trapped in their snowed-in vehicles, but many died of hypothermia. Others may have died from carbon monoxide poisoning after running their car heaters for long periods of time, said Rehman.

Pakistan Meteorological Department said a strong westerly wave was affecting most parts of the country and may persist until Sunday [Inter Services Public Relations via EPA-EFE]

PM announces inquiry

Prime Minister Imran Khan expressed shock over the “tragic deaths”.

“Have ordered inquiry and putting in place strong regulations to ensure prevention of such tragedies,” Khan said in a tweet.

Located about 50km (22 miles) north of the capital, Islamabad, Murree is a popular winter resort that attracts well over one million tourists annually. Streets leading into the city are often blocked by snow in winter.

Videos shared on social media showed entire families, including children, lying dead in their snow-covered vehicles.

Snowfall, which began on Tuesday night, continued at regular intervals, attracting thousands of tourists. Because of the huge numbers of visitors, many families ended up getting stranded on roads.

“This is an example of systemic failure because according to reports, about 100,000 vehicles headed to the hill station, one that has narrow roads,” said Al Jazeera’s Kamal Hyder, reporting from Islamabad.

“There were warnings of heavy snow and that led to a total catastrophe because people were stuck in their vehicles, entire families. Their vehicles were buried under heaps of snow.”