Super Cyclone Pam smashed into the island archipelago late Friday, bringing sustained winds of more than 155 miles per hour and causing widespread damage. Six people were killed and 30 injured in the capital Port Vila alone, Agence France-Presse reported.
Aid agencies estimate more than 90 percent of housing has been damaged or destroyed in the capital, which has a population of about 45,000.
About 1,000 people had sought shelter in evacuation centers in Port Vila as the storm passed over, officials said.
Aid agencies worry about the safety of tens of thousands of people living on the southern islands just as the authorities are struggling to reestablish communications with communities there after the storm finally swept out to sea late Saturday.