The US Navy ship USS Harry S Truman hit a merchant ship Besiktas-M late Wednesday evening off Port Said, Egypt, in the Mediterranean Sea.

The incident happened at around 11:46 p.m. local time on February 12, according to a release from the US Navy’s Sixth Fleet. The 100,000-ton Nimitz-class aircraft carrier hit the 53,000-ton Panamanian-flagged cargo ship in a rare accident between two such big ships at sea.

No flooding or injuries were reported on board the Truman, which has a crew of around 5,000 sailors. The Navy stated that the aircraft carrier’s nuclear power plant system was not affected, and the vessel was safe and stable.

An investigation is being launched to identify why the collision took place.

The USS Harry S Truman strike group has been going back and forth in the Red Sea in mid-December to deter Houthi militant attacks on merchant ships. The carrier temporarily stopped at a naval facility in Crete earlier this week for a unusual operational respite, after a long deployment period.

Although tensions in the area are still high, operations had eased somewhat following a ceasefire between Israel and Hamas in mid-January. The Houthis have asserted that their attacks on commercial shipping were carried out in solidarity with Hamas.

The Sixth Fleet has assured that naval operations are unaffected by the incident. More information regarding the investigation and possible damage to the ships is to be expected in the next few days.