Eight of the 22 who died at mountain resort town of Murree were from the family of a police officer who also died, another Islamabad police officer said.

The cause of death in most cases was hypothermia, officials said.

So far, it is known that 10 men, 10 children and two women have died.

Thousands of vehicles had to be pulled from the snow, interior minister Sheikh Rashid Ahmed said, but more than a thousand were still stuck in the area on Saturday.

Videos posted online showed cars struggling to stay on the road away from the resort in blizzard-like conditions.

Murree, 28 miles (45km) north of the capital of Islamabad, is visited by more than a million people annually. Roads into the city are often blocked by snow in winter.

It was founded during the colonial era as a 'hill station' where British administrators could escape the heat of the plains but has since become a resort popular with domestic tourists.

More than 4ft (1.2m) of snow fell in the area overnight, the interior ministry said, and all incoming traffic was unable to reach the town on Saturday.

Mr Ahmed said paramilitary troops and a special military mountain unit had been called on to help.

He added: "Until then, no vehicle or even people on foot are allowed to enter Murree except for the emergency and rescue vehicles and those bringing food for the stuck people."

Khan shocked and upset

Pakistani Prime Minister Imran Khan tweeted that he was shocked at what had happened.

He said on Twitter: "Shocked & upset at tragic deaths of tourists on road to Murree. Unprecedented snowfall & rush of ppl proceeding without checking weather conditions caught district admin unprepared.

"Have ordered inquiry & putting in place strong regulation to ensure prevention of such tragedies."

Rescue efforts during the night were hampered by the amount of snow, authorities said, with heavy snow clearing equipment getting stuck at first.

Food and blankets have been distributed to those caught up in the bad weather.