Tehran, Apr 2 (AFP) Iranian Foreign Minister Javad Zarif accused the United States of impeding aid efforts and "economic terrorism" Tuesday as authorities ordered the immediate evacuation of flood-stricken cities in western Iran.

US sanctions are "impeding aid efforts by #IranianRedcrescent to all communities devastated by unprecedented floods," Zarif tweeted, referring to search and rescue operations being conducted after huge rainfalls triggered vast flooding.

"Blocked equipment includes relief choppers," the tweet read, adding that "this isn't just economic warfare; it's economic TERRORISM." The evacuation was ordered after rivers burst their banks, dams overflowed and vast areas were cut off from communication.

A chronic shortage of rescue helicopters in Iran, due to US sanctions, has forced the emergency services to request help from military helicopters and amphibious armoured personnel carriers to assist in the rescue operations.

The authorities declared a "situation red", the highest level of alert, in Lorestan province with four or five cities "completely critical", state television news network IRINN reported from Khorramabad, the region's capital.

"In Khorramabad the water has risen by as much as three metres (nearly 10 feet) in parts... and reports are coming in of regions... completely submerged with residents stranded on their rooftops," it added.

The Red Crescent's provincial director, Sarem Rezaee, said his organisation had lost contact with much of the region.

"Telephones are not working, our radio communications are down... at this moment we have no news of other cities and villages," he told IRINN, adding roads were flooded and helicopters were unable to take off due to the bad weather.

"We have requested emergency help from neighbouring provinces but at the present no one can do anything." The airport in the western city of Khorramabad was flooded, with images showing water submerging the runway and cutting the province's main air link to the rest of the country.

Authorities in Lorestan ordered evacuations in many regions, bringing in the armed forces to forcibly remove those who do not comply, local media reported. (AFP)

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