The exercise was conducted in the Strait of Hormuz, a strategic waterway through which many of the world’s oil and cargo shipments pass, as well as in the Gulf of Oman, the Gulf of Aden and the northern Indian Ocean, IRNA reported. Accounts in the state-run news media said the war games covered a 400,000-square-mile area.

Iran holds military exercises regularly to demonstrate its defense capabilities in the strategic Persian Gulf region, where about 30 percent of the world’s energy supplies are transported. The United States Navy maintains a carrier force in the area and stations its Fifth Fleet in Bahrain. American forces conduct naval exercises with other countries in the region, including the United Arab Emirates and Saudi Arabia.

The news agencies did not say that the exercises were directed against a specific threat, but tensions with the United States have been percolating over an American-led campaign of international sanctions devised to pressure Iran over its disputed nuclear energy program. Iran has previously threatened to close the Strait of Hormuz in retaliation for the sanctions.

In December, Iran said that the naval forces of Iran’s Islamic Revolutionary Guards Corps captured an American drone that had entered its airspace over the Persian Gulf. Officials identified it as a ScanEagle, built by Boeing, an aircraft that can be launched and operated from ships, the company said on its Web site. The United States Navy denied losing any drones, but the unmanned aircraft could have been operated by the C.I.A. or the National Security Agency.

Several Persian Gulf countries also have ScanEagle drones.

Pentagon officials said in November that Iranian warplanes had fired on a Predator drone, believed to be the first time Iranian warplanes had fired on an American drone. Iran said the Predator had violated is airspace, an assertion that American officials dismissed.