Iranian authorities warned Tuesday that a second sandstorm could hit Tehran, a day after freak weather killed five people in the capital.
Monday's huge sandstorm and record winds plunged Tehran into darkness for 15 minutes during rush hour and forced thousands to run for cover.
"One of the casualties, who was hospitalised after being hit by debris, lost his life due to the severe injuries," the official IRNA news agency reported Tuesday, raising the death toll to five.
The winds, as high as 110-120 kilometres per hour (70-80 miles per hour), levelled trees and swept other heavy material across streets and into the windscreens of cars as people headed home from work.
The news of the sandstorm and highest winds in 50 years hit the first page of capital's newspapers, along with criticism of forecasters for failing to predict or warn citizens of the approaching storm.
The surprise weather disrupted a ceremony for the national football team before they depart for the World Cup in Brazil, with President Hassan Rouhani cancelling his planned speech, leaving a 12,000-seat stadium largely empty.
Ahad Vazifeh, head of Tehran's weather forecasting and warnings unit, said his team had informed "relevant authorities" about the sandstorm. However, he said the timescale and wind speeds were not completely predictable.
His comments appeared to be the response for the anger in some media towards his department for failing to give adequate warnings.
But Mohammad Ali Aziz-Oghli, the city's chief forecaster, warned of another sandstorm hitting Tehran at about 3:00 pm (1030 GMT), albeit not of the same strength. People should stay indoors, he told IRNA.
Power supplies were knocked out in at least 50,000 homes Monday, an electricity official said. The weather also smashed windows and caused telecommunication towers to topple and masonry to peel off buildings.