A rescue operation remains under way to free two beached whales, despite the death of 22 others who were stranded on Tasmania's Ocean Beach.

Marine biologists and wildlife staff guided two sperm whales and one Minke whale back to the ocean, but nothing could be done for the rest of the whales that surfaced just off Macquarie Harbour on the state's west coast.

As the carcasses are left to decompose, scientists will conduct studies to determine what caused the mass suicide.

Al Jazeera’s Andrew Thomas reports from Australia's capital, Sydney.