The deadly double earthquakes in Iran over the weekend, the first natural disaster there since the United States imposed onerous financial sanctions on that country because of its disputed nuclear program, have raised worries among Iranian Americans about where to send donations — and whether such aid is even legal.

U.S. officials said Monday that humanitarian aid for victims of the disaster, which left more than 300 people dead and thousands homeless in a Turkish-speaking region of northwest Iran, was exempt from sanctions. But the National Iranian American Council, a Washington-based advocacy group representing Americans of Iranian descent, said the U.S. ban on financial transactions, which applies to two dozen Iranian banks, including the central bank, had made U.S. banks reluctant to deal with any monetary transfers to Iran, even if they were permitted.

Trita Parsi, the president of the council, said the only practical alternative for Iranian Americans who wanted to help the quake victims was to send money via family remittances, which are permitted under the sanctions.

Iran on Monday raised its earthquake death toll to 306.

Americans have no simple way to send relief aid to Iranian victims. Major international relief organizations like the Red Cross, Mercy Corps and AmeriCares said Monday that they were not accepting donations, for now, because Iran had not asked for their help.

Many countries have expressed condolences and offered emergency relief supplies. But Pooya Hajian, a spokesman for Iran's Red Crescent Society, said Iran would not accept aid from any country, only from other Red Cross organizations.