At least eight people died as Cyclone Pam tore through Vanuatu, an aid worker said Sunday, and communications remain severed with outer islands in the South Pacific archipelago.

“This was a cyclone that flattened houses and, unfortunately, to find missing people and those who are unaccounted for, it is going to take a huge search and rescue effort,” Chloe Morrison, a World Vision emergency communications officer, said by phone from the capital, Port Vila. “Connections have been down here, so we haven’t had any reports in from the outlying islands either.”

Morrison said officials from Vanuatu’s National Disaster Management Office confirmed to her agency that eight people had died during the storm, and further meetings with updates would be held during the day.

Pam made a late change of course to hit Vanuatu directly early Saturday, tearing through the islands with winds as strong as 170 miles per hour. Australian Foreign Minister Julie Bishop said Saturday her country stood ready to assist Vanuatu and was “deeply concerned” by reports that an estimated 40 people may have died in the north of the archipelago.

“It’s absolute devastation here,” Morrison said. “The roads are littered with trees, roofs have flown off buildings and are strewn everywhere, houses were literally picked up and flattened like an Ikea flat-pack.”

People who left evacuation centers to return to their villages found their homes damaged or blown away, Morrison said. Winds had dropped and the weather cleared Sunday, she said.

United Nations Secretary-General Ban Ki-moon said he was concerned that damage and destruction could be widespread.

“We hope the loss of life will be minimal,” Ban said Saturday at a conference on disaster risk and reduction in Japan, according to a statement.

Vanuatu President Baldwin Lonsdale, also attending the conference, said he still didn’t know the impact of the cyclone.

“I am speaking to you today with a heart that is so heavy,” he said. “I stand to appeal on behalf of the government and the people to give a helping hand in this disaster.”

The UN children’s agency estimated that 54,000 children were among those affected.

Australia is preparing to send a crisis response team to Vanuatu, Bishop said Saturday. “We are still assessing the situation, but we stand ready to assist,” she said.

Also Saturday, New Zealand pledged $733,000 to help with relief efforts.

Vanuatu, an archipelago of about 80 islands, was a British-French colony until it gained independence in 1980. Home to some 277,000 people, it’s located about 1,500 miles northeast of Sydney.