WASHINGTON - The US Navy said on Friday that it has rescued 13 Iranian hostages held by Somali pirates in Arabian Sea, days after tension escalated as Iran warned against the return to the Gulf by a US aircraft carrier strike group.

The US guided-missile destroyer USS Kidd, part of the USS John C. Stennis aircraft carrier strike group which just departed the Gulf days ago, responded to a distress call from the Iranian boat Al Molai, held by Somali pirates for more than 40 days, the US Navy said in a statement.

A US Navy team from the USS Kidd was taken by a helicopter to board the Iranian boat, used as a "mother ship" by the pirates, and detained 15 pirates, who surrendered quickly without any resistance.

"The Al Molai had been taken over by pirates for roughly the last 40-45 days," said Josh Schminky, a Navy Criminal Investigative Service agent aboard the Kidd. "They were held hostage, with limited rations, and we believe were forced against their will to assist the pirates with other piracy operations."

The Iranians were freed and headed home after the US Navy team gave them food, water and medical care.

The rescue operation came amid rising tension between the US and Iran, whose military chief on Tuesday warned Washington against sending the aircraft carrier back to the Gulf. The USS John C. Stennis was sent to the Gulf to observe the 10-day Iranian naval exercises that started from Dec 24. The US rejected this warning, saying it will continue to deploy its aircraft carriers to the Gulf to protect freedom of navigation.

Iran, facing increased sanctions by the US and its allies over its nuclear program, threatened last week to close the Strait of Hormuz, one of the world's most critical oil route, if its oil exports are sanctioned by the West. In response, the Pentagon warned that "interference with the transit or passage of vessels through the Strait of Hormuz will not be tolerated."