SYDNEY  - A Sri Lankan refugee boat with 200 people believed to be on board capsized off Australia's remote Christmas Island Thursday, with police saying scores could have died.Late Thursday, Australia's Maritime Safety Authority (AMSA) said 110 people had been rescued after the mid-afternoon accident in Indonesian waters, according to ABC television. It is the latest in a series of refugee boat disasters in the Indian Ocean in recent years, as rickety, overloaded vessels packed with desperate migrants sink on their way to Australia.The ship issued a distress call and capsized 120 nautical miles north of Christmas Island, some 2,600 kilometres (1,600 miles) from the Australian mainland, AMSA said, and 200 people were thought to be on board. Western Australia police commissioner Karl O'Callaghan said a "large number" were feared to have perished.  "Some of the very early reports suggest that up to 75 people may have drowned, but I do stress that they are unconfirmed at this stage," O'Callaghan told reporters. "We are very concerned for a large number of people who may have drowned," he added. "We know from what we've been hearing from the aircraft that there's not 200 life jackets on board."AMSA said the cargo ship WSA Dragon and Australian military vessel HMAS Wollongong were on the scene to recover survivors from the water, while a defence aircraft dropped life-rafts which could hold 60 people. "We can also confirm that survivors are wearing life jackets," an AMSA spokeswoman said.All aircraft and the two Australian military ships deployed had night search capabilities and operations would continue through the hours of darkness, she added, with another two merchant ships and two Indonesian navy boats en route.Gagah Prakoso, a spokesman for Indonesia's search and rescue service which is co-ordinating the operation, said the boat was an asylum-seeker vessel "coming from Sri Lanka and going to Christmas Island".Though they come in relatively small numbers by global standards asylum-seekers are a sensitive political issue in Australia, dominating 2010 elections due to a record 6,555 arrivals.Direct asylum-seeker journeys from Sri Lanka have historically been rare but navy sources in Colombo have reported a marked increase in Australia-bound people smuggling operations, with some 200 arrests in recent weeks.Indonesia is a more common transit point for those trying to reach Christmas Island, which is closer to Java than mainland Australia, but many fail to reach their destination.In December, a boat carrying around 250 mostly Afghan and Iranian asylum-seekers sank in Indonesian waters on its way to Christmas Island, with only 47 surviving.Some 50 refugees were killed in a horror shipwreck on the island's cliffs in December 2010. Fifteen were children aged 10 years or younger, with one a baby just three months old.The worst known refugee boat disaster off Australia in recent years was the sinking of the SIEV X in 2001, which killed 353 of the more than 400 asylum-seekers on board.Australian Prime Minister Julia Gillard said she spoke with Indonesian President Susilo Bambang Yudhoyono on the sidelines of a UN environment summit in Rio after the latest accident."At this stage details are sketchy but what is apparent is there has been a large loss of life at sea," she told reporters. "This is a very distressing and tragic incident."So far this year 62 vessels carrying 4,484 boatpeople have been intercepted off Australia, an unprecedented number in a six-month period.Arrivals have increased steadily since Canberra was forced to abandon a so-called "people swap" deal with Malaysia by the High Court last year and roll back its mandatory detention policy for boatpeople.A number of asylum boats have been intercepted in the area in the past 24 hours, prompting Home Affairs Minister Jason Clare to issue a statement calling for an urgent political compromise."Let's remember what this is all about - 200 people died off the coast of Indonesia and another 11 died off the coast of Malaysia," Clare said in a statement earlier Thursday, referring to previous recent accidents.