Iran test-fired more long-range missiles on Thursday in a second day of exercises aimed at showing the country can defend itself against any attack by the US or Israel, state television reported.
The weapons fired overnight have "special capabilities" and included missiles launched from naval ships in the Persian Gulf, as well as torpedoes and surface-to-surface missiles, the broadcast said. It did not elaborate.
A brief video clip showed two missiles being fired simultaneously in darkness.
US Secretary of State Condoleezza Rice warned Iran that Washington will not back down in the face of threats against Israel.
"We are sending a message to Iran that we will defend American interests and the interests of our allies," Rice said in Georgia at the close of a three-day Eastern European trip.
Among the missiles Iran said it tested yesterday was a new version of the Shahab-3, which officials have said has a range of 2,000 kilometres and is armed with a 1-ton conventional warhead.
That would put Israel, Turkey, the Arabian peninsula, Afghanistan and Pakistan all within striking distance.
Wednesday's missile tests were conducted at the Strait of Hormuz, a strategic waterway at the mouth of the Persian Gulf through which about 40 per cent of the world's oil passes. Iran has threatened to shut down traffic in the strait if attacked.
Oil prices jumped on news of yesterday's tests, rising USD 1.44 to USD 137.