DUBAI/GENEVA (Reuters) - Iranian authorities ordered the evacuation of scores of villages on Tuesday as the impact of severe flooding spread further across the country, while Washington denied Tehran’s claim that U.S. sanctions were slowing aid efforts.

FILE PHOTO: Damaged vehicles are seen after a flash flooding in Shiraz, Iran, March 26, 2019. Tasnim News Agency/via REUTERS

At least 47 people have been killed in the past two weeks from flash floods after the worst rains in the country in at least a decade.

State television said armed forces had stepped up relief efforts, airing footage of military and Red Crescent helicopters taking part in rescue operations.

Flood risks forced authorities to order the evacuation of more than 70 villages in the oil-rich southwestern province of Khuzestan, state news agency IRNA said.

Iran’s top authority, Supreme Leader Ayatollah Ali Khamenei, praised rescue efforts but said officials should have anticipated the disaster better, state TV reported, as a war of words broke out between Tehran and Washington over relief responses.

Iranian Foreign Minister Mohammad Javad Zarif said on Monday that U.S. sanctions - reimposed after Washington quit a 2015 nuclear deal between Iran and six world powers - were impeding aid efforts to all affected communities.

“Blocked equipment includes relief choppers: This isn’t just economic warfare; it’s economic TERRORISM,” he said on Twitter

In a response that Zarif described as fake news, U.S. Secretary of State Mike Pompeo said on Tuesday that Washington was ready to help via the Red Cross and Red Crescent, and accused Iran’s clerical establishment of “mismanagement in urban planning and in emergency preparedness”.

“The regime blames outside entities when, in fact, it is their mismanagement that has led to this disaster,” Pompeo said in a statement.

IRNA said Germany and Britain, both signatories to the nuclear deal, had offered humanitarian aid, including 40 boats.

Flooding has affected at least 26 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.

Iranian media said on Tuesday that 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 villages.

President Hassan Rouhani, accused by critics of mishandling the flooding crisis, has promised compensation to all those affected.

Authorities are concerned about increasing threats of river dam failures that could wreak more damage and, with the capital Tehran was on alert for possible flooding, officials urged people to stay away from vulnerable areas.