Officials in the Solomon Islands have declared a national state of emergency after a major earthquake in the South Pacific sparked a tsunami that destroyed at least one town and killed at least 15 people.

The death toll was expected to rise as the military and emergency crews reach the remote areas Tuesday to assess the damage, a spokesman for Prime Minister Manasseh Sogavare said.

(CBC)

The magnitude 8.0 quake hit about 45 kilometres southeast of Gizo, New Georgia Islands, at about 7:40 a.m. local time Monday, the U.S. Geological Survey said.

Following the quake, a tsunami crashed ashore on Gizo. Several people were missing and presumed dead, police said.

"Some people were seen floating on the sea during the big waves but it was very difficult to go near them," Alfred Maesulia, the information director in Sogavare's office, told the Associated Press late Monday. 

Judith Kennedy, a resident reached by telephone, said all the houses near the sea had been flattened and a lot of houses in the downtown area collapsed.

Supplies being flown in

Shop owner Danny Kennedy said boats were left in the middle of the road.

Maesulia said residents of Simbo, Choiseul and Ranunga islands near Gizo also reported deaths and widespread destruction.

"There are reports that some villages were completely washed away," he said. "Sasamungga village is quite a big village. … It was reported that 300 houses were completely destroyed in that village alone."

Solomon Islands Deputy Police Commissioner Peter Marshall said three military helicopters would fly to the stricken region Tuesday with supplies for the homeless.

The Hawaii-based Pacific Tsunami Warning Center issued a warning for the Solomon Islands and neighbouring Papua New Guinea. Warnings were lifted within hours for areas outside the Solomons.

In Australia Monday, officials closed beaches along the length of the country's east coast, stopped ferry services in Sydney and warned fishing boats to return to port in precautionary measures that were lifted by the end of the day.

A tsunami may also have come ashore at Willis Island and Cooktown in far northeastern Australia, the Australian Bureau of Meteorology's National Meteorological and Oceanographic Centre said.

An official at the Canadian High Commission in Canberra, Australia, told the Canadian Press by telephone that no Canadians are reported to be in the areas affected by the tsunami.

With files from the Associated Press