The U.S. Navy has seven combat ships in the waters around Yemen as the Saudi-led bombing campaign there continues, but U.S. troops are not participating in a Saudi naval blockade in the region, U.S. military officials said Friday.

The American ships include: the destroyers USS Forrest Sherman and USS Winston Churchill; the minesweepers USS Sentry and USS Dextrous; and three amphibious ships carrying about 2,200 Marines, the USS Iwo Jima, the USS New York and the USS Fort McHenry, a Navy official told The Washington Post. The USNS Charles Drew, a dry cargo ship, is also in the region.

The Navy regularly patrols the Gulf of Aden and Red Sea around Yemen, but the ships there now are deployed at a sensitive time with the Saudi Navy blocking deliveries to Yemen’s ports. The Saudis began the operation last month in an apparent attempt to stop Houthi rebels in Yemen from re-arming.

Iran, which has been accused of arming the rebels, responded by sending navy vessels of its own into the region this week. The ships are said to be positioned in the Bab al-Mandab strait, the narrow stretch of water between Yemen and Djibouti that connects the Red Sea and the Gulf of Aden.

The Wall Street Journal reported this week that the United States had expanded its role at sea around Yemen, searching vessels for Iranian arms bound for the rebels. But Air Force Col. Patrick Ryder, a spokesman for U.S. Central Command, downplayed the effort on Friday, saying the United States is not a part of the Saudi-led blockade and is simply patrolling waters in the region the way it usually does.

Lt. Timothy Hawkins, a Navy spokesman at the Pentagon, said the service has not boarded a ship in the region since April 1, when troops from the USS Sterett, a destroyer, boarded the Panamanian-flagged ship Saisaban. It was suspected to be carrying weapons from Iran to Yemen, but nothing was found.

The United States routinely searches ships in the region. In one 2013 example, Force Reconnaissance Marines with a maritime raid force boarded a ship looking for an insurgent leader off the coast of Yemen. They didn’t find him, but their commanding officer said the Navy often looked for weapons smuggling on small ships known as dhows.

Fierce fighting between a Saudi-led coalition and the Iran-backed rebels in Yemen resulted in the death of at least one member of the Saudi ground force. (Reuters)