A Pearl Harbor-based submarine was damaged when a periscope struck an unidentified vessel Thursday in the Persian Gulf, the Navy said.

U.S. Naval Forces Central Command said in a statement that no one was hurt in the pre-dawn incident involving the USS Jacksonville.

The submarine surfaced from periscope depth to see whether the collision damaged the vessel, but the ship continued “on a consistent course” offering no indication of distress or acknowledgement of a collision.

The Navy says one of the Jacksonville’s two periscopes was damaged and that a P-3 Orion aircraft searched the area but saw no debris in the water or vessels in distress.