TEHRAN, JUNE 27 -- Iran's spiritual leader, Ayatollah Ali Khamenei, today expressed gratitude for the millions of dollars of foreign aid that has poured into the country since a devastating earthquake killed an estimated 50,000 people last Thursday.

Addressing an audience at a Tehran mosque, Khamenei praised "the Moslem countries and the other countries of the world {who} felt a responsibility. . . . I thank them all."

Khamenei's remarks, reported by Tehran radio this afternoon, were the first public endorsement by a senior government official of the large-scale foreign assistance that Iran has continued to accept, even from adversaries such as the United States, in the aftermath of the worst earthquake in its history.

The comments appeared calculated to bolster the position of President Ali Akbar Hashemi Rafsanjani, whose openness to Western aid has provoked criticism from some Islamic radicals in his government.

As a spiritual and political authority, Khamenei is the successor to the late Ayatollah Ruhollah Khomeini. Although he is regarded as an important figure in Iran's government, Khamenei lacks the charisma of his predecessor, who led Iran's radical Islamic revolution in 1979.

Since last week's earthquake, 175 planes from scores of countries have arrived at Tehran's airport, bearing medicine, food, blankets, tents and other relief supplies. Considerably more aid is expected by Iranian officials during the next two weeks.

In Washington, the State Department announced the release of an additional $470,000 worth of assistance. The money, sent through the American Red Cross, paid for tents, medical supplies, emergency generators and the cost of chartering a plane to carry the supplies to Iran, according to spokeswoman Margaret D. Tutwiler. The planeload, scheduled to arrive late today, brings the total of official U.S. aid so far to about $760,000, she said, adding that American private organizations have donated $1.7 million in supplies and cash.

{Bad weather was blamed for the crash of a Chinook relief helicopter with 14 people on board that hit a mountain in Gilan province, the Associated Press reported. One person died and six were reported seriously injured. The official Iranian news agency, IRNA, identified the man killed as Mohammed Hossein Eftekhari, a parliamentary deputy from Rudbar. IRNA said a relief worker also died Wednesday in Rudbar when a wall collapsed during a mild aftershock.}

Meanwhile, Wahid Dastjerdi, president of the Iranian Red Crescent Society, which has directed most of the relief operations, told a news conference today that rescue efforts in the earthquake region were drawing to a close and that foreign relief teams in the area would leave Iran within one or two weeks.

"We do not believe there is anyone left under the debris and most of the {injured} victims have been evacuated," said Dastjerdi. "After a week . . . there will be no need at all for relief teams from outside."

Dastjerdi said he had received no confirmed reports of survivors being discovered under the debris from collapsed homes and stores. He said the foreign relief teams that had brought dogs and sophisticated listening devices to search for trapped victims were disappointed.

The statements by Dastjerdi and other Red Crescent officials were at odds with reports by IRNA that at least six people were rescued Tuesday after five days trapped beneath their collapsed homes. IRNA said that in Kshom village near the flattened town of Rudbar, a 40-year-old woman and her 12-year-old son were dug out from under five feet of rubble by a joint Iranian-French team.

The agency also reported that a 6-year-old boy survived for four days and five nights in a refrigerator in the village of Veih before being rescued and that three other victims were dug from the rubble of Jirandeh village Tuesday.

Compared to other earthquakes of similar magnitude there have been relatively few survivors in the devastated regions of northwestern Iran because the homes and buildings that collapsed were built from mud and straw and had few structural beams, making it less likely that pockets of air would be formed in the rubble where survivors might breathe.

Red Crescent officals said they had so far delivered 70,000 blankets, 1,000 tons of food and 300,000 sets of clothes to Gilan and Zanjan provinces, where damage was greatest. They said that after an initial delay caused by bad roads, relief supplies had now reached all the isolated villages in the mountainous region.

Mohammed Parham, general secretary of the Iranian Red Crescent, said 105,000 families -- approximately a half-million people -- had been left homeless in Gilan and Zanjan provinces. He said about 10,000 units of prefabricated housing had already been moved to the area but he said more would be needed and he expressed hope that foreign donors would contact Iranian authorities about how to assist with temporary housing for the homeless.

Dastjerdi said Iran's Health Ministry dispatched 400 sanitation teams to the northwest, including some that used helicopters to spray devastated areas with chemicals to prevent outbreaks of disease from decomposing bodies or contaminated water. He said that so far, there had been no reports of cholera or other contagious diseases sometimes associated with the aftermath of a natural disaster.

Red Crescent officials praised the generous donations of food, clothing and cash made by ordinary Iranians at local mosques and shipped to the northwest by army and government trucks. They said they had no accurate account of the private donations but they were still pouring in.

While Iran continued to accept aid from Saudi Arabia, Khamenei sharply attacked that country today over the issue of the annual Islamic pilgrimage to Mecca, Reuter reported. Iran has boycotted the event since 1988, when Saudi Arabia put quotas on the number of pilgrims a year after more than 400 people, most of them Iranians, died in a clash with Saudi security forces during a demonstration in Mecca.

"Our hearts ache for being barred from the House of God," Khamenei said, "but this act of the enemies of Islam and their mercenaries will lead to still greater glories for Islam." He said Iran "will never make a deal with the Saudi regime" on the matter.