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.

Pakistan ordered businesses, schools and public offices in Karachi to shut on Wednesday after torrential monsoon rain left at least 10 people dead in the densely populated port city, with more heavy downpours predicted.

Pakistan's Karachi continued to reel under the impact of unprecedented monsoon rains on Tuesday, which have claimed at least six lives, as reported by Dawn. Karachi Mayor Murtaza Wahab has declared a rain emergency amid warnings of more showers to come.