Flash floods triggered by torrential rains have killed at least 344 people in northern Pakistan in the past 48 hours, officials said on Saturday.

The majority of deaths, 328, were reported in mountainous Khyber Pakhtunkhwa province, the Provincial Disaster Management Authority said.

The meteorological department has issued a heavy rain alert for Pakistan's northwest for the next few hours, urging people to take"precautionary measures".

Hundreds of rescue workers are still searching for survivors in Buner, a mountainous district in Khyber Pakhtunkhwa province where torrential rains and cloudbursts triggered massive flooding on Friday, said Mohammad Suhail, a spokesman for the emergency services. Dozens of homes were swept away.

According to local authorities, flash floods killed at least 650 people this week in Northern Pakistan.

Such cloudbursts are increasingly common in India’s Himalayan regions and Pakistan’s northern areas, and experts have said climate change is a contributing factor.