At least 25 people were killed as flash floods hit northwestern Iran, state media reported on Saturday.
Sixteen others were declared missing after torrential rains hit four provinces.
Television footage has shown streets inundated with water, and cars being swept away.
“Twenty-five people have been killed in the floods across four provinces,” the head of Iran’s emergency response organization, Esmail Najar, told the ISNA news agency.
Iranian media reported that the flood had also triggered a landslide.
Torrential rains that began on Friday struck East Azerbaijan province, with state television showing images of rivers bursting their banks, flooded houses and cars being swept away by the surging water.
The areas of Ajab Shir and Azar Shahr in East Azerbaijan are the worst hit, according to AFP news agency.
A rescue operation is under way.