A powerful sandstorm has hit Iran's capital, Tehran, killing at least four people and injuring about 30.
At its peak, the storm brought winds of up to 110km/hour (70mph), knocking over trees and damaging windows.
Eyewitnesses told the BBC the sky turned orange from thick dust brought on by the storm. Such strong storms are unusual in Tehran, correspondents say.
The storm caused power cuts and traffic accidents from poor visibility as dust and sand engulfed parts of the capital.
Some domestic flights to central Iran have been diverted, AP news agency reports.
'Everywhere went dark'
One shopkeeper in Tehran, identified only as Nouri, told AP news agency: "It was a horrifying storm and suddenly everywhere went dark.
"I closed my store's shutters to prevent damage. [A] big tree broke and knocked in the windows, shattering them."
The total number of deaths is unclear. Iranian state television said five were killed, while state-run Irna news agency said four died.
Some of the deaths were reportedly caused by falling trees.