A tanker enroute from Singapore to Songkhla, Thailand was boarded by 6 pirates armed with guns in a speed boat. They took all the crew hostage, hit a few crew with their guns and damaged the navigation and communication equipment. They then sailed the tanker to an unknown location where part of the gas oil cargo was stolen and transferred into another vessel. Before escaping the pirates stole crew personal belongings and ship’s properties. After the pirates departure, the crew sailed to a safe port.