The US Fifth Fleet says a search operation is underway in the Arabian Sea after a US sailor went overboard from the aircraft carrier USS Abraham Lincoln, the AP reports. The statement Thursday said two US ships, a Spanish frigate, and a Pakistan naval ship are conducting a search-and-rescue operation. The sailor, whose name was withheld in line with navy policy, has been missing since Wednesday. The Abraham Lincoln was routed to the Arabian Sea in recent weeks in what US officials say is a deterrence amid heightened tensions between the US and Iran. (More Navy stories.)