An Iranian militia held civil defense drills on Sunday to prepare for any air strikes and the military said it could close a waterway crucial for world oil supplies if Iran was attacked.

The exercises organized by student members of the Basij militia were held at hundreds of schools across the country and involved transporting wounded people and putting out fires after a fictitious bombardment by enemy planes.

The United States and Israel have hinted they could take military action if Iran presses ahead with a nuclear program they believe is aimed at making atomic bombs.

Iran, which says the program is for peaceful purposes, says it will retaliate for any strikes against it.

State television showed pictures of ambulances with sirens wailing rushing to the scene of a simulated attack and people lying on the ground with bloodied faces.

Officials also reiterated that Iran was ready to close down the Strait of Hormuz, a sea route at the mouth of the Gulf through which 40 percent of the world's traded oil passes, if the United States attacked.

Navy Commander Rear Admiral Habibollah Sayari said foreign forces in the region were being closely watched and Iran would not allow any foreign ship to enter its waters.

"We are capable of closing the Strait of Hormuz," he told told IRNA news agency.

Rasoul Sanairad, a senior Basij political officer, said the strait provided "an exceptional opportunity" for defending the nation, according to Fars News Agency.

Military experts say Iran's armed forces cannot match U.S. military technology but could still cause havoc on shipping routes, particularly using small craft for hit-and-run attacks.

Iran's navy will hold exercises in December involving missile-equipped battleships and scuba-diving special forces, state radio said.

The Basijis are a paramilitary force estimated to have 12 million members who uphold Islamic revolutionary values. In the 1980s war with Iraq, they provided much of the manpower for the front. In peacetime, they help enforce Iran's strict Islamic dress and other moral codes.