Australian maritime authorities say a boat carrying about 200 asylum seekers has capsized off the coast of Australia's remote Christmas Island.

The vessel sank about 220 kilometers north of Christmas Island on Thursday. The Australian Maritime Safety Authority say three merchant vessels and two Australian naval ships are heading towards the site.

The authority says survivors have been spotted in the water.

Australia is a major destination for people fleeing impoverished, war-torn countries such as Afghanistan, Iraq and Sri Lanka. Many of them are crammed into crowded detention centers on Christmas Island and the Australian mainland.

About 50 asylum seekers died when the leaking, wooden boat they were traveling struck the island's rocky cliffs in December 2010.