The death toll from heavy rain in Pakistan that caused flash floods and collapsed houses has risen to 53 over the past three days, a senior disaster management official said.

The deaths reported by Brigadier Kamran Zia spanned the entire country.

He said 12 were in the north-west's semi-autonomous tribal region, eight in neighbouring Khyber Pakhtunkhwa province, and three in the Pakistan-held part of the disputed Kashmir region.

Brig Zia, a member of the National Disaster Management Authority, said 12 people died in central Punjab province, 10 in south-western Baluchistan, and eight in southern Sindh.

He said flooding was especially bad in Pakistan's largest city, Karachi, because of the southern city's faulty drainage system.

The same storm system hit Afghanistan, killing at least 58.