US President Bush offered assistance despite the major differences the U.S. has with Tehran over its nuclear program.

"We, obviously, have our differences with the Iranian government, but we do care about the suffering of Iranian people," Bush said at a news conference with the leaders of Mexico and Canada.

Secretary of State Condoleezza Rice, visiting northern England, expressed "deep sympathy" to the Iranians.

Washington had not received an Iranian request for U.S. military aid, and none was being provided, Defense Department spokesman Bryan Whitman said Friday.

The U.S. military provided aid to the residents of Bam after the south Iranian city was devastated by an earthquake in 2003 that killed 26,000. Washington and Tehran have no diplomatic relations and are currently at loggerheads over U.S. claims that Iran is trying to develop nuclear weapons ¡ª a charge Iran denies.

Most of the 1,200 people injured Thursday and Friday had been in bed when the quake struck, state television said.

After the first quake struck Thursday evening, police in the city of Boroujerd and the town of Doroud toured the streets with loudspeakers urging people to leave their homes for fear of aftershocks. The warnings are thought to have contributed to a lower death toll than is usual in Iran for quakes of this magnitude.

Twelve aftershocks were registered after the first quake, said Nabi Bidhendi, the head of Tehran University's Geophysics Institute.

Such quakes have killed thousands of people in the past in the countryside where houses are often built of mud bricks.

Barani, the disaster official, told the official Islamic Republic News Agency that rescue teams had been sent to the region. Television showed survivors standing next to their destroyed homes.

Barani said hospitals in the cities of Doroud and Boroujerd were full and could not receive further injured. Officials recalled doctors and nurses from vacation to help treat the injured. Iranians are celebrating Nowruz, the Iranian New Year, and most government offices are closed.

Iran is located on seismic fault lines and is prone to earthquakes. It experiences at least one slight earthquake every day on average.