DUBAI, United Arab Emirates (AP) — Two U.S. Navy warships operating in the Mideast have been affected by the coronavirus, authorities said Friday, with one already at port in Bahrain and another heading to port now.

A dozen troops aboard the USS San Diego, an amphibious transport dock, tested positive for COVID-19, said Cmdr. Rebecca Rebarich, a spokeswoman for the Bahrain-based 5th Fleet. The ship is at port in Bahrain.

“All positive cases have been isolated on board, and the ship remains in a restricted COVID bubble,” Rebarich told The Associated Press. “The port visit and medical support have been coordinated with the host nation government and Bahrain Ministry of Health.”

The second ship, the guided-missile cruiser USS Philippine Sea, has “several person under investigation” for possible coronavirus infections, Rebarich said. The ship is expected to pull into port for further testing at a location she declined to name, citing “operational security.”

The San Diego has a capacity to carry nearly 700 personnel, while the Philippine Sea can carry over 300.

The 5th Fleet patrols the waterways of the Mideast. Its vessels often have tense encounters with Iran in the Persian Gulf and the Strait of Hormuz, the narrow mouth of the Gulf through which 20% of all oil traded worldwide passes.