Nov. 2 (Bloomberg) -- An Australian air force helicopter arrived at the scene of a capsized boat off the coast northwest of Perth to help search for more than 20 people missing, the Australian Customs and Border Protection Service said.

As many as 19 people were rescued by two commercial vessels from Taiwan and the Bahamas, Australian Prime Minister Kevin Rudd said in an interview with the Australian Broadcasting Corp.

The boat may have carried as many as 40 people, Home Affairs Minister Brendan O’Connor told Sky television news today. An Australian ship is on its way to the area in Australia’s search and rescue zone, some 2,400 kilometers (1,500 miles) from the mainland, and is scheduled to arrive tomorrow.

The group’s nationality and the purpose of the voyage aren’t known, O’Connor said, responding to local media reports that the boat was carrying asylum seekers bound for Australia. Rudd’s government is under pressure to cut the number of people arriving in Australian waters seeking refuge and is accused by opposition lawmakers of weakening border controls.

The priority is “seeking to ensure the safety of life at sea for all involved,” Rudd told reporters in Townsville, northeastern Australia, earlier today.

“The question as to why they’re there, at this point, is not a priority for the Australian Maritime Safety Authority,” O’Connor said. “It’s a very large area for us to assist and we are doing that in these very difficult circumstances.”

Asylum Seekers

Australia’s Greens party spokeswoman Senator Sarah Hanson- Young called for a “compassionate approach” to be adopted toward those rescued. “We believe that all survivors should be brought to Australia for treatment and if there are any asylum seekers among this group, they should have their claims processed here,” she said in a statement.

The opposition says more than 40 boats carrying almost 2,000 migrants have been intercepted at sea since August last year. Many of the passengers are Sri Lankans or Afghans, smuggled through transit points in Malaysia and Indonesia.

Rudd’s government has blamed the surge in part on people smugglers who charge thousands of dollars in return for passage to Australia by ship.

Many of the so-called asylum seekers are held at Christmas Island, located some 2,600 kilometers northwest of Perth, the capital of the state of Western Australia.

Rudd is preparing to double the capacity of the Christmas Island detention center to hold as many as 2,300 people to cope with the rising number of migrants, the Australian newspaper reported on Oct. 31.

Australia will take a tough approach to people smugglers, Rudd said today.

To contact the reporter on this story: Nichola Saminather in Sydney at nsaminather1@bloomberg.net.

Last Updated: November 2, 2009 01:55 EST