Australia's bureau of meteorology said a 25-centimeter tsunami already hit Australia's remote Cocos Island early Tuesday and bigger tidal surges were expected to strike Australia's west coast.

Phil Cummins of the government's Geoscience Australia said that although no major tsumani had yet been reported near the quake epicenter off Indonesia's Sumatra island, a big tidal surge could still be heading across the Indian Ocean towards Africa.

"I would say there is still potential for this to have generated a large tsunami," Cummins told AFP.

Australia's bureau of meteorology initially reported that the tsunami measured just 10 centimters at Cocos Island, located in the deep waters of the Indian Ocean south of Sumatra, but later upgraded that to 25 centimeters.

"That's fairly big for the deep ocean," Cummins said of the wave which hit Cocos, adding that an alert had been issued for a one-meter surge expected to hit the west Australian coast.

This was the same magnitude of the tsunami which struck the area after the December 26 quake.

Asked if the east coast of Africa could still be struck by a major tsunami from the latest quake, Cummins said: "I would say it's still something we have to regard as a possibility."

"We've seen the thing at Cocos Island and that really does tell us we have to exercise caution," he said.

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