Rahmatullah Afzaly says the thought of boarding a rickety Indonesian fishing boat in roiling seas, crammed with hundreds of other asylum seekers, is terrifying. But it's nothing compared to his fear of the Taliban.

His lips quiver and he struggles to keep the tears inside as he allows his memory to drift back home to Afghanistan, where scores of ethnic Hazaras like himself have been captured, tortured and killed by Islamic militants.

He and thousands of other asylum seekers from various war-ravaged and impoverished countries have made it to Indonesia, but Australia is where they seek a better life. And they are risking death to find it.

Unwilling to languish for years here in detention centers while their cases are heard, many board smugglers' boats to attempt the 500-kilometer (300-mile) trip to Australia's Christmas Island.

Concern over the journey has escalated in the past three weeks.