WASHINGTON (AP) — The U.S. has struck multiple Iranian tankers in response to more attempted missile attacks on a Navy warship, according to a U.S. official, who spoke Tuesday on condition of anonymity to discuss sensitive military operations.

It marks the latest tit-for-tat strikes as Washington and Tehran lurch back toward fighting during more than six months of war.

Iran’s Revolutionary Guard Navy has warned crews of oil tankers near ports in Kuwait and Bahrain to immediately leave their vessels, saying the ships could be targeted in retaliation for U.S. attacks on Iranian tankers.

The warning, carried by Iranian state television, said the U.S. military had targeted several Iranian oil tankers. It accused Kuwait and Bahrain of hosting U.S. forces and assisting in the attacks.

The Revolutionaly Guard warned tanker crews to abandon their vessels whether they were at anchor or docked, saying they “will be targeted.”