Pakistani rescuers on Sunday found the bodies of two schoolchildren hit by an avalanche in the mountainous northwest, while around nine more remain buried beneath the snow.

The disaster struck on Saturday afternoon near the village of Susom, some 40 kilometres (24 miles) north of the town of Chitral in Khyber Pakhtunkhwa province, local police station chief Sultan Baig told AFP.

Worried parents and authorities began searching for the ninth graders when they did not return from school.

"The chances of finding any survivors are very low," said local deputy mayor Mohammad Ali. "But you never know, people have been found alive buried under snow for nearly 20 hours."

The Provincial Disaster Management Authority said Sunday evening the rescue operation was still continuing.

Heavy rains have killed at least 86 people, injured 101 and damaged 240 houses since March 9 across Pakistan, according to the National Disaster Management Authority. It said landslides and collapsed roofs caused most of the fatalities.

Poorly-built homes, particularly in rural areas, are most prone to collapse.

Severe weather hits the country every year, with hundreds killed and huge tracts of prime farmland destroyed in recent years.