Pirates Attack Japanese Oil Tanker off Malaysia

Malaysian marine police officers inspect the Naniwa Maru 1 at Klang port, Malaysia after the Singapore-owned tanker was robbed by pirates, April 23, 2014.

Pirates have kidnapped three crew members and seized millions of liters of diesel fuel in an attack on a Japanese tanker off Malaysia's west coast.

Malaysian police say six armed pirates approached the tanker on a speedboat, climbed aboard, and locked up most of the ship's crew members early Tuesday.

The pirates were able to transfer about three million liters of diesel fuel onto two nearby vessels before escaping with three Indonesian hostages.

The Japanese tanker was headed from Singapore to Burma, also known as Myanmar. It was attacked in the Strait of Malacca, through which much of the world's oil supply flows.

Pirate attacks in the strait have been reduced in recent years thanks to increased patrols and other safety measures, but there was an uptick in the number of attacks last year.

Authorities have not said who they believe is responsible for Tuesday's attack.