At least 50 people have been killed in heavy rains and lightning across Pakistan in the past three days, officials said, as authorities declared a state of emergency in some regions.

Farmers harvesting wheat died after being struck by lightning. Rains caused dozens of houses to collapse in the northwest and in eastern Punjab province.

Arfan Kathia, a spokesman for the provincial disaster management authority, said 21 people had died in Punjab, where more rains were expected this week.

Khursheed Anwar, a spokesman for the disaster management authority in northwestern Khyber Pakhtunkhwa province bordering Afghanistan, said 21 people died there.

Torrential rains also lashed the capital, Islamabad, and killed seven people in southwestern Baluchistan province. Streets flooded in the northwestern city of Peshawar and Quetta, the Baluchistan capital.

Rafay Alam, a Pakistani environmental expert, said such heavy rainfall in April was unusual.

“Two years ago, Pakistan witnessed a heatwave in March and April and now we are witnessing rains and it is all of because of climate change, which had caused heavy flooding in 2022,” he said.

In 2022, downpours swelled rivers and at one point inundated one-third of Pakistan, killing 1,739 people. The floods also caused $30bn in damage.