Iran tests missiles, vows to hit back if attacked

The United States also has forces based in nearby Arab states, including Qatar and Bahrain, along with ships patrolling the Gulf waterway.

Iran has said U.S. forces are vulnerable because of their presence in two of its neighbors, Iraq and Afghanistan.

Israel, believed to be the Middle East's only nuclear-armed power, has vowed to prevent Iran from acquiring an atomic bomb.

"Israel does not threaten Iran, but the Iranian nuclear program, combined with their aggressive ballistic missile program, is a matter of grave concern," Mark Regev, spokesman for Israeli Prime Minister Ehud Olmert, said after the tests.

Leaders of the Group of Eight rich countries voiced serious concern on Tuesday at the proliferation risks posed by Iran's nuclear work. World powers have offered Iran incentives if it will suspend uranium enrichment. Tehran has rejected the demand.

Iran has threatened to close the Strait of Hormuz, conduit for about 40 percent of globally traded oil, if it is attacked. The U.S. military says it will prevent any such action.

The war of words heightens risks that a misunderstanding or a minor clash in the Gulf, for instance, could get out of hand.

Tehran and Washington have not had diplomatic ties for almost 30 years and have few avenues for direct communications.

An aide to Iran's Supreme Leader was quoted as saying on Tuesday that his country would hit Tel Aviv, U.S. shipping in the Gulf and U.S. interests in reply to any military strike.

Analysts say Iran's military technology often involves improving weaponry originating in China and North Korea.

"They are some way away yet from threatening Israel or U.S. bases," said London-based independent military analyst Paul Beaver, adding guidance systems over longer ranges needed work. But he said the missile program was still "pretty advanced."

(Additional reporting by Hossein Jaseb, Writing by Fredrik Dahl and Edmund Blair, editing by Alistair Lyon and Charles Dick)