Across Pakistan, monsoon rains that began in late June have been heavier than usual, killing at least 645 people. Four hundred of those deaths were in the northwest alone, where narrow valleys and river-carved gorges funnel rainwater into sudden torrents.

Anguished Pakistanis searched remote areas for bodies swept away by weekend flash floods as the death toll reached 277 on Monday.

Officials say rescuers have recovered dozens more bodies from collapsed homes in a northwestern district of Pakistan, bringing the death toll to at least 274, as authorities defended their response to the flooding.