Reports are emerging that Iran has two U.S. Navy boats in its custody but Iran says that the crew members will be returned “promptly.”

Iran claims that the 10 Americans entered Iranian waters illegally and were arrested by the Islamic Revolutionary Guard Corps.

According to ABC News, Pentagon spokesman Peter Cook told the Associated Press, “We have been in contact with Iran and have received assurances that the crew and the vessels will be returned promptly.”

Editor’s note: This breaking news story has been updated with additional tweets.