Sydney- A boat carrying around 50 asylum-seekers was intercepted by Royal Australian Navy patrol boats Tuesday off Australia's west coast, bringing the number of boats to arrive this year to 11.

Seven boats arrived last year, giving rise to worries among Australian officials of an upsurge in mostly Sri Lankan Tamil, Afghan and Middle Eastern undocumented immigrants.

Home Affairs Minister Bob Debus said the latest batch was taken aboard the HMAS Maryborough and would be sent to the immigration detention centre on Australia's Indian Ocean territory of Christmas Island.

More than 280 asylum-seekers have arrived so far this year by boat. Eighteen boats have arrived since the government of Prime Minister Kevin Rudd softened Canberra's treatment of illegal arrivals in August.

Under former prime minister John Howard, boats were intercepted and those on board were taken to Pacific island countries that hosted offshore immigration centres on Canberra's behalf, where they were processed under United Nations rules, which are stricter than Australia's own rules.

The so-called Pacific Solution was credited with stopping the flow of unwanted arrivals but discontinued by Rudd because it was deemed inhumane.