An Australian military plane dropped an inflatable life raft Monday to dozens of apparent asylum seekers clinging to wreckage of a boat that sank in the Indian Ocean far from shore. Up to 11 others were still missing and one person was confirmed dead.

Two merchant ships that responded to distress calls from the stricken vessel had rescued 27 people by Monday night, including those who swam to the life raft, Australian officials said. One person taken aboard a rescue vessel died, Home Affairs Minister Brendan O'Connor said.

"At this stage, 11 people appear to be missing, and there are grave concerns for their safety," O'Connor said in a statement.

The boat went down late Sunday about 400 miles from the Cocos Islands, sparsely populated atolls about 1,500 miles northwest of the Australian coast and about 800 miles south of Indonesia.

Government officials said it was too early to say whether those on board were asylum seekers trying to reach Australia, though aspects of the emergency -- such as an unseaworthy boat carrying so many people in waters sometimes used by human traffickers -- signaled that may be the case.

"All the efforts right now are legitimately dedicated to attending to lives at risk at sea," Prime Minister Kevin Rudd told reporters. He noted the remote region was "a very difficult search environment."

Stephen Langford, regional medical director for the Royal Flying Doctor Service that sent a plane to assist the search, said it was a race against time to find more survivors.

"It's a fairly urgent task because there's still people in the water, and the weather is not fantastic," he told reporters.

An air force cargo plane reached the area Monday afternoon after hours of flying, and spotted two survivors in the water, O'Connor said. It dropped a life raft to them and continued to scour the search zone. Rudd said later that three other people who were clinging to timber were also seen paddling toward the raft.

A second military plane was on its way, along with the plane from the doctors' service, a medical charity specializing in medical emergencies in remote Outback areas.

Rhianne Robson of the Australian Maritime Safety Authority, which was coordinating the search and rescue operation, said the stricken ship was in Australia's maritime search and rescue zone when it sent out distress calls. The authority sought help from vessels in the area because the emergency was so remote, Robson said.

A Taiwanese fishing trawler and the merchant ship LNG Pioneer arrived in the area late Sunday and deployed life rafts and began plucking people from the water.

Air Chief Marshal Angus Houston, the chief of Australia's defense forces, said the stricken boat was intact when the rescue vessels first arrived.

"Somehow or other during the process of the interaction between the ship and the trawler and also the stricken vessel, there's been a capsize and people have ended up in the water," Houston told reporters.

There has been a surge of boats carrying asylum seekers toward Australia. Some 35 boats carrying about 1,770 asylum seekers have arrived in Australian waters this year, mostly from Iraq, Afghanistan, Iran and Sri Lanka.

Many of them pay thousands of dollars to people smugglers who send them to sea in leaky boats from Indonesia and sail south. Most are caught by customs authorities and are detained in an immigration camp on remote Christmas Island while their refugee applications are assessed, a process that can take months or years.