Pakistan has issued a flood alert for some southern districts, warning of torrential rains, as rescue teams continued searching for missing people in the northwest, where severe floods have killed hundreds over the past week.

Officials say rescuers have recovered dozens more bodies from the rubble of collapsed homes in a northwestern district of Pakistan, bringing the death toll to at least 274, as authorities defended their response to the flooding and said they did not need any foreign help at this point.

At least 21 people have died in monsoon rain-related incidents in Pakistan, authorities said, pushing the nationwide death toll over the last week above 400 as floods and landslides continue to devastate large parts of the country.