JAKARTA, Indonesia - A ferry carrying more than 200 people sank off Indonesia's Sumatra island, possibly due to bad weather, police said Sunday.

The Dumai Express was sailing from Batam island to Pekanbaru in Riau province when it went down at around 10am (0300 GMT) off Karimun island near Singapore, local police official Boy Herlambang told AFP.

"The ship's manifest listed 213 passengers and 13 crew members including the ship's captain," he said. "Right now, many of them are still floating in the water and we're trying to rescue them as quickly as possible.

"The boat sank likely due to heavy rain and big waves and it is difficult to get to them because of bad weather conditions."

Indonesia's 234 million people are spread across 17,000 islands and are heavily dependent on a network of ships and boats, which have a poor safety record.

Up to 335 people were killed when a ferry sank off Sulawesi island in January. In December 2006 a ferry went down in a storm off the coast of Java, killing more than 500 people.