Rescuers were struggling to retrieve bodies from debris after flash floods triggered by heavy monsoon rains across northern Pakistan killed at least 321 people in the past 48 hours, authorities said on Saturday.
The majority of deaths, 307, were reported in mountainous Khyber Pakhtunkhwa province, AFP quoted the Provincial Disaster Management Authority as saying.
Most were killed in flash floods and collapsing houses, with the dead including 15 women and 13 children. At least 23 others were injured.
The provincial rescue agency told AFP that around 2,000 rescue workers were engaged in recovering bodies from the debris and carrying out relief operations in nine affected districts where rain was still hampering efforts.
"Heavy rainfall, landslides in several areas, and washed-out roads are causing significant challenges in delivering aid, particularly in transporting heavy machinery and ambulances," Bilal Ahmed Faizi, spokesman for Khyber Pakhtunkhwa's rescue agency, told AFP.
"Due to road closures in most areas, rescue workers are travelling on foot to conduct operations in remote regions," he added.
"They are trying to evacuate survivors, but very few people are relocating due to the deaths of their relatives or loved ones being trapped in the debris."
The provincial government has declared the severely affected mountainous districts of Buner, Bajaur, Swat, Shangla, Mansehra and Battagram as disaster-hit areas.
The meteorological department has issued a heavy rain alert for Pakistan's northwest for the next few hours, urging people to take "precautionary measures".
Nine more people were killed in Pakistan-administered Kashmir, while five died in the northern Gilgit-Baltistan region, the national disaster authority said.
Another five people, including two pilots, were killed when a local government helicopter crashed due to bad weather during a relief mission on Friday.
The monsoon season brings South Asia about three-quarters of its annual rainfall, vital for agriculture and food security, but it also brings destruction.
Landslides and flash floods are common during the season, which usually begins in June and eases by the end of September.
Syed Muhammad Tayyab Shah, a representative of the national disaster agency, told AFP that this year's monsoon season began earlier than usual and was expected to end later.
"The next 15 days... the intensity of the monsoon will further exacerbate," he said.
