The hurricane damaged villages in the coastal provinces of Hormuzgan, Kerman and Sistan-Baluchestan and knocked out electricity and telecommunications in some areas, officials said. Roads, bridges and villages were also hit.
"1,850 villages in Sistan-Baluchestan, Kerman and Hormuzgan provinces are having difficulties receiving aid," Hossein Bagheri, head of the national disaster organisation, told the web site of Iran's state broadcaster IRIB.
"In some places the height of the water reached two metres."
IRIB quoted Bagheri as saying 23 people had died, of whom 20 drowned in villages. Two aid workers were among the dead.
Iranian media on Saturday said 12 people were killed. Cyclone Gonu killed 49 people in Oman.
Another Iranian official, Abdollah Raisi, said a dam 40 km (25 miles) north of the town of Nikshahr had been destroyed, the official IRNA news agency said.
Bagheri said the priority was to provide drinking water to people as well as to restore power and telecommunications.
"Most of the problems are in the villages of Sistan-Baluchestan," he said, giving a total damage estimate of 2,000 billion rials (roughly $216 million).
Gonu had raised fears of a disruption to exports from the Middle East, origin of more than a quarter of the world's oil. Oil prices rose to around $71 a barrel on Thursday.
Officials in Iran and Oman have said conditions were gradually returning to normal.
- Reuters - Thomson Reuters Foundation
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