Rescuers were battling Monday to reach thousands of people stranded by floods and landslides in Pakistan's northwest and parts of Kashmir, officials said, as the death toll rose to 61.

Disaster management officials in Khyber Pakhtunkhwa province, where 51 people have died since the downpour began Saturday night, said bad weather was hampering the rescue and relief operation.

"Death toll has been risen to 51, at least 150 houses have been destroyed," an official of the Provincial Disaster Management Authority told AFP, requesting anonymity as he was not authorised to talk to media.

Latifur Rehman, a spokesman for the Authority, told AFP that rescue workers had not been able to reach three affected districts in the far-flung mountainous north of the province.

"Bad weather is the main reason, we are yet unable to send helicopters to these areas," Rehman said.

Rehman said they had received reports that at least 180 houses had been destroyed in those areas.

"We need to get bodies and the injured out from under the rubble and provide food and tents to the survivors," Rehman said, adding that four truckloads of supplies had been sent to affected districts.

"All roads leading to villages and other areas have been blocked... There is no movement at all," Khalid Khan, a courier company owner in Shangla district of Khyber Pakhtunkhwa, told AFP, adding that local hospitals lack the facilities to deal with the injured.

In Pakistan-administered Kashmir's Neelum Valley, officials said thousands were stranded by landslides.

At least ten people, including five children, died there when two houses were buried in a landslide caused by the rains, Raja Moazzam, a spokesman for local disaster management authority told AFP.

Mainly dry weather was expected in most parts of Pakistan from Monday, according to the meteorological department's website, though thunderstorms were still predicted for Kashmir.

Poorly-built homes across the country, particularly in rural areas, are prone to collapse during the annual spring rains, which are often heavy.

Severe weather hits Pakistan annually, and in recent years hundreds have been killed and huge tracts of prime farmland destroyed, which has delt a heavy blow to the largely agrarian economy.

During the rainy season last summer, torrential downpours and flooding killed 81 people and affected almost 300,000 across the country and in Kashmir.