Student members of the Basij Iranian militia held civil defense drills on Sunday to prepare for any air strikes that might be dictated by a failure of diplomacy to stop the Islamic Republic's uranium enrichment program, according to Reuters. The United States and Israel have hinted they could take military action if Iran presses ahead with the program, which could be used for making nuclear warheads.

Officials also repeated a warning that if the United States attacks, Iran is ready to close down the Straits of Hormuz, a sea route for 40 percent of the world's crude oil.