By Li Hongmei

Pirates hijacked a second tanker in a month off the Malaysian coast near Singapore, Asia's biggest oil-trading hub, according to the International Maritime Bureau.

Ten pirates armed with guns and knives boarded a tanker about 7.3 nautical miles (13.5 kilometers) west of Malaysia's Pulau Kukup in the Strait of Malacca, forcing the crew to transfer gasoil from the vessel to another ship, the IMB's Piracy Reporting Center said in a Nov. 7 incident report on its website. The attack was about 34 miles west of Singapore, according to the co-ordinates recorded by the agency.

The U.S. Energy Information Administration identifies the Malacca Strait, which connects the Indian Ocean with the South China Sea and Pacific Ocean, as one of the world's two "most strategic chokepoints" for oil trade along with the Strait of Hormuz in the Persian Gulf. It is the shortest sea route between the Middle East and Asia with about 15.2 million barrels of oil a day transported along the waterway in 2011, according to the EIA. About 90 percent of that was crude.

A fishing vessel was the only ship to be hijacked in the Strait of Malacca in all of last year, according to the IMB's website. Two Kuala Lumpur-based officials from the organization were not available for comment when contacted by phone and e-mail today.

The incident follows the hijacking of an oil-products tanker off Malaysia's Pulau Aur in the South China Sea on Oct. 10, about 67 miles northeast of Singapore. Pirates stole the ship's cargo before abandoning it on Oct. 15, the IMB's website shows. The Regional Cooperation Agreement on Combating Piracy and Armed Robbery against Ships in Asia reported that a vessel called the Danai 4, carrying marine gasoil from Singapore to Vietnam, lost contact with its owners in the area on Oct. 10, according to an alert on its website.