Samoa's deputy Prime Minister Misa Telefoni said islanders had no warning that a killer tsunami was barreling towards their coastline in the early hours of this morning.

Samoa's disaster management office said up to 100 people may have been killed after giant waves hit the islands' coastlines early this morning, following an 8.3 magnitude earthquake in the ocean south-west of American Samoa.

The disaster management office's assistant chief executive Ausegalia Mulipola said teams are still searching for victims, with some villages and resorts in the country's south-east completely destroyed.

Telefoni has told the ABC that resorts on the southern coast of Upolu is completely gone.

Foreign Affairs Minister Stephen Smith has confirmed that seven Australians have been injured and are being treated in hospital.

Smith who was briefed on the quake when he arrived in Singapore a short time ago said Australia is sending a task-force of officials to Samoa in the next 24 hours.