On October 12, 2000, a boat filled with explosives with a suicide bomber of Al Qaeda rammed against a US destroyer named USS Cole in the Aden harbour. In the resulting explosion, 17 US naval personnel were killed and the ship was severely damaged. A subsequent enquiry brought out that a US naval officer on watch duty on the deck of USS Cole had seen the boat approaching USS Cole at high speed, but he did not fire on it and sink it. The rules of engagement of the US Navy then in force reportedly provided that US naval personnel should fire upon inside a harbour only if fired at. Since the Al Qaeda boat did not open fire, it was not fired at and sunk before it could ram against USS Cole. In justification of the seeming inaction of the officer on watch duty, it was stated during the enquiry that inside busy harbours such as that of Aden, many small boats operated by the harbour management keep moving around for providing logistics. It would have been difficult to assess the hostile intent of an approaching boat inside the harbour.
