THE Royal Australian Air Force flight ASY789 arrived at Sydney Airport just after 9pm last night with a group of bewildered and worried evacuees from Tonga.

Sharon Simpson, 55, stayed on the island last week while her husband sailed their boat to New Zealand.

"I felt on Thursday afternoon that things were not right," she said. "Then I saw them setting fire to the buildings. I tried to grab a cab to the airport. A family drove me out … It is so out of character for Tonga because the Tongans are normally very kind and very generous."

Esa Kava, an Australian living in the island nation, was concerned about its ability to bounce back.

"It is a small economy," she said. "It will be hard to recover. I will not be going back for the time being."

Australia sent 50 military personnel and 34 police on Saturday to support the local security forces trying to stabilise the situation, after the Tongan Government requested help on Friday. New Zealand also sent peacekeepers.

The Minister for Foreign Affairs, Alexander Downer, told the ABC's Insiders program yesterday that the situation was "quiet at the moment". In the riots last Thursday - linked to a pro-democracy movement - public buildings and shops were attacked and looted, and at least eight people were killed.

"Hopefully there won't be any more problems and we'll be able to withdraw fairly soon," Mr Downer said.

Australia also has three naval vessels in international waters in the South Pacific, which the Defence Force says could be used to assist Tonga should the violence flare up again.

In a statement yesterday it said the Australian forces had joined their New Zealand counterparts and "planning will occur with the Tongan security forces to confirm the way ahead in returning normalcy to Nuku'alofa", the capital.

There are about 300 Australians in Tonga.

Mr Downer said the New Zealanders had secured the airport in Tonga, and commercial flights would be available from today if more people wished to leave.

The riots erupted when legislators looked likely to adjourn for the year without a decision on expanding democracy, enraging pro-democracy activists.

Calm was restored on Friday after an emergency meeting of the cabinet, nobles and elected commoners agreed to pro-democracy demands. Legislators elected by popular vote will represent the majority in Parliament at the next election in 2008, ending centuries of rule by nobles and people appointed by the royal family.

The Tongan police commander, Sinilau Kolokihakaufisi, said despite the calm the central district remained closed to civilians.

The New Zealand Prime Minister, Helen Clark, said the Tongan Prime Minister, Fred Sevele, was upset by the riots and the violence his family had experienced when they were forced to flee a supermarket as the mob approached.

"He's still very shocked at what happened, not helped by the fact that his wife and daughter, I understand, were at the supermarket," Miss Clark said yesterday. "It was a very traumatising experience for them."

The ABC reported yesterday that leaders of Tonga's democracy movement had condemned the intervention of Australia and New Zealand soldiers.