The owner of a tour company on nearby Mystery Island Benie Masauvakalo said a surge of water moved inland but people had fled to higher ground.
Mr Masauvakalo, who was speaking from Port ViIla, said he had reports from his staff that the water moved about 200 metres inland.
He said schools and two or three houses had been damaged but no one was hurt and the schools were not occupied at the time.
"The tide actually followed the river mouth. Those houses are standing by the river and got washed off."
Mr Masauvakalo said his kayaks were washed inland.