Flood risks forced Iranian authorities to order the evacuation of over 70 villages in the oil-rich southwestern province of Khuzestan on Tuesday, the state news agency IRNA reported.
State television said the armed forces, including the elite Revolutionary Guards corps, had stepped up relief efforts in flood-stricken areas, airing footage of military and Red Crescent helicopters taking part in rescue operations.
Iranian media said electricity and telecommunications had been cut in affected areas, roads had been washed away and people were waiting on rooftops to be rescued in some inundated villages.
At least 47 people have been killed in the past two weeks from flash floods in provinces from the north to the south of the sprawling Islamic Republic after the most torrential rains to hit the country for at least a decade.
Flooding has affected at least 26 out of Iran’s 31 provinces since heavy downpours began on March 19. A state of emergency was declared in several provinces and tens of thousands of people have been evacuated from homes in flooded locales.
IRNA said Germany and Britain has offered humanitarian aid to Iran, including 40 boats, but Iranian officials said renewed U.S. sanctions against Tehran had disrupted some relief efforts.
"In an inhuman and outrageous approach...because of America's blockage of the (Iranian) Red Crescent's bank accounts..., no foreign or Iranian nationals outside Iran will be able to send aid to flood-stricken people," Foreign Ministry spokesman Bahram Qasemi told IRNA on Tuesday.
In May last year, President Donald Trump withdrew the United States from world powers' 2015 nuclear deal with Iran and reimposed U.S. sanctions on the Iranian banking and energy sectors that had been lifted under the deal.
Iranian President Hassan Rouhani, accused by critics of mishandling the flooding crisis, has promised compensation to all those affected. Judiciary chief Ibrahim Raisi has said that officials suspected of having mishandled the disaster and caused the death of civilians could face prosecution.
Authorities are concerned about increasing threats of river dam failures that could wreak more damage in various provinces.
State officials urged people to stay away from rivers and areas near dams and said all relevant organisations were on high-alert due to possibility of flooding in the capital Tehran.