Severe weather has forced the provincial government to declare a state of emergency in Karachi's hospitals, with holidays cancelled for doctors and paramedics, they said.

Most of the city was inundated by knee-deep rainwater, causing traffic chaos.

Authorities have closed schools and colleges due to transportation difficulties and hazards like falling power lines.

Four of the dead were reportedly electrocuted by power lines wrecked by the rainstorms in several areas of the city.

Officials said Karachi had received 142mm (more than 5.5 inches) of rain in the previous 24 hours, with more expected.