Iranian Revolutionary Guards launched rockets near the U.S. aircraft-carrier Harry S. Truman and other warships as they were entering the Gulf on Saturday, giving only brief notice in a “highly provocative” act, a U.S. military spokesman said on Tuesday.

“The rockets were not fired at the Truman and other ships, only near them,” the spokesman said.

Several Revolutionary Guard vessels fired the rockets “in close proximity” of the warships and nearby merchant traffic “after providing only 23 minutes of advance notification,” said Navy Commander Kyle Raines, spokesman for the U.S. Central Command.

“These actions were highly provocative, unsafe, and unprofessional and call into question Iran’s commitment to the security of a waterway vital to international commerce,” Raines said in an email.

The Truman, accompanied by two warships from the U.S.-led coalition supporting air strikes against Islamic State militants in Iraq and Syria, was entering the Gulf through the Hormuz Strait on a routine transit when the incident occurred, he said.

“While most interactions between Iranian forces and the U.S. Navy are professional, safe, and routine, this event was not and runs contrary to efforts to ensure freedom of navigation and maritime safety in the global commons,” Raines said.

Iranian and U.S. forces have clashed in the Gulf in the past, especially during the Iran-Iraq war in the 1980s after the 1979 Islamic revolution.

Tehran and six world powers including the United States clinched an agreement in July that would curb Iran’s nuclear program in return for lifting economic sanctions.

The U.S. aircraft carrier USS Harry S. Truman came about 1,500 yards from an Iranian rocket in the Strait of Hormuz last week, two U.S. military officials told on Tuesday.

As the Truman was transiting the strait, which connects the Arabian Sea and the Persian Gulf, Iranian Revolutionary Guards conducted a live-fire exercise right near the U.S. carrier Saturday, officials said.

The official said the U.S. ships were in the “internationally recognized maritime traffic lane” at the time, not in any territorial waters, when the Iranian navy announced over maritime radio that it was about to conduct a live-fire exercise and asked other vessels to remain clear.

There was no direct communications between U.S. and Iranian navies, the official added.

Coalition forces continued transiting without any further incident, the official said, adding that the Truman is now in the Gulf and launching aircraft in support of Operation Inherent Resolve.

Nobody from Iran’s foreign or defense ministries gave an official comment, but the country’s state-run news agency, Fars, said in its report of the event that no vessel was in danger.

The incident was a planned training exercise and all vessels in the area had been warned, it said.