At least 21 people were killed in flash floods caused by heavy rains in Iran's southern Fars province, state media said on Saturday.
Khalil Abdollahi, head of the province's crisis management department, said heavy rains near Soltan Shahbaz village in Estahban caused flooding from the Rodbal Dam, official Irna news agency reported.
A number of people were still missing and efforts to find them were under way.
Estahban is about 170 kilometres south of Shiraz, the capital city of Fars.
Videos shown on local media and posted on social media showed cars caught in the rising waters of the Rodbal river and carried away.
Iran has endured repeated droughts over the past decade, but also regular floods.
In 2019, heavy flooding in the country's south left at least 76 people dead and caused damage estimated at more than $2 billion.
In January, at least two people were killed in flash flooding in Fars when heavy rains hit the area, a local official said at the time.
Scientists say climate change amplifies extreme weather, including droughts as well as the potential for the increased intensity of rain storms.
Like other nearby countries, Iran has suffered chronic dry spells and heatwaves for years, and these are expected to worsen.
In the last few months, demonstrations have occurred against the drying up of rivers, particularly in central and south-western Iran.
Last November, tens of thousands of people, including farmers, gathered in the dry riverbed of the country's Zayandeh Rood river in the country's central region, to complain about the drought and blame officials for diverting water.
