Pakistani disaster relief officials issued fresh flood warnings Sunday after the death toll from heavy monsoon rains rose to 45 and waters paralyzed parts of the largest city Karachi.

Flash floods caused by monsoon downpours have inundated some main roads in the sprawling port city and swept away homes in the northwestern province of Khyber Pakhtunkhwa.

In neighboring Afghanistan, flash floods caused by days of torrential rain have killed more than 40 people, mostly in Surobi district east of Kabul.

Pakistan's National Disaster Management Authority warned that more thunderstorms and heavy rains were expected on Monday and some rivers may flood.

At least 45 people have been killed in the floods over the weekend. Officials in Karachi said at least 19 had died in the city to add to 20 dead in the northwest and six in the southwestern province of Baluchistan.

Doctor Semi Jamali at the Jinnah Hospital in Karachi told Agence France Presse that most of the deaths occurred due to electrocution or collapsing roofs and walls.

Prime Minister Nawaz Sharif sent three of his cabinet ministers to inspect damage in flood-hit areas.