Floods caused by a week of heavy rain have killed more than 1,000 people in Pakistan’s northwest and rescuers battled on Sunday to distribute relief to tens of thousands of trapped people.

A westerly weather system moving in from Iran and Afghanistan, combined with heavy monsoon rain, caused the worst floods on record in Pakistan in the past week, with the northwestern province of Khyber-Pakhtunkhwa the worst hit.

Provincial Information Minister Mian Iftikhar Hussain told Pakistani media more than 1,000 people had been killed and the toll could be even higher. In Afghanistan, dozens of people were killed and thousands were rescued after flash floods in the northeast.