A Hong Kong-registered oil tanker was reported to have caught fire after it collided with a cargo ship in waters off Busan, South Korea, early yesterday morning. At about 2.15am, South Korean time, oil tanker Maritime Maisie, which weighs more than 29,000 tonnes, collided with the 55,000-tonne freighter Gravity Highway. The Gravity Highway was on a test run in waters about 9.2 nautical miles off the southeastern port city of Busan. According to South Korea's Yonhap news agency, the impact caused two of the 20 chemical containers on board the tanker to go up in flames. The South Korean authorities deployed 16 coastguard boats, some navy vessels and helicopters to the scene for rescue. Firefighters brought the blaze under control at about 10am. About 4,000 tonnes of the chemicals paraxylene and acrylonitrile were lost in the blaze. All 27 crew members on the tanker were rescued by the South Korean coastguard. Some sustained light burns or abrasions, but none were seriously injured. The cargo vessel, which had 64 crew members on board, also caught fire, but it was quickly extinguished. The vessel was then towed to a nearby shipyard. Yonhap quoted South Korean officials as saying the coastguard would move the rest of the chemicals and fuel from the tanker to another vessel before towing it. They said there is a risk it will split in two and sink as the crash left an eight-metre hole on one side and it is tilting at a 20-degree angle. South Korean officials said they were investigating the cause of the crash. A spokesman for Hong Kong's Marine Department confirmed that the locally registered ocean-going tanker was loaded with chemicals while sailing to Ningbo from Busan. All 27 people on the vessel were rescued, he added.