Flash floods and landslides triggered by heavy rain have killed at least 26 people and destroyed hundreds of houses in northern Pakistan, officials said on Thursday.

Chaudhry Abdul Majeed, the prime minister of Pakistan-administered Kashmir said at least 17 people have been killed and nine others injured in six districts since Monday.

"Some 685 houses and 125 shops have been damaged and roads washed away," Majeed said, adding that a request has been made to the federal government for financial help.

Irshad Bhatti, a spokesman for the country's National Disaster Management Authority, said the extent of the damage was still being assessed.

The majority of the deaths in Kashmir came when buildings collapsed due to the rains, and a further nine people died in flooding in the northwestern province of Khyber Pakhtunkhwa, officials said.

Adnan Khan, an official from the Khyber Pakhtunkhwa, said he feared the death toll there could rise.

"Dozens of families have suffered and their houses were destroyed, several people are still missing" Khan told AFP.

Weather officials are predicting heavy rain in the next three days and rescue teams are closely monitoring the situation, Bhatti said.

Floods in Pakistan in the summer of 2011 affected 5.8 million people, with floodwaters killing livestock, destroying crops, homes and infrastructure as the nation struggled to recover from record inundations the previous year.