Key Points:

Nuku'alofa remains sealed off by road blocks as a crime scene after eight people died in rioting and as much as 80 per cent of businesses were destroyed.

Ministry of Foreign Affairs and Trade spokeswoman Helen Tunnah said from Tonga: "There are still road blocks in place and no-one can go into the central business district without permission.

"The restricted access is very tight because it has been declared a crime scene."

The electricity supply had improved, although there were still food shortages after supermarkets were looted and destroyed.

It is estimated as many as 80 per cent of businesses in Nuku'alofa's central business district were destroyed in the rioting.

Deputy Prime Minister Michael Cullen said today that New Zealand soldiers were not sent to Tonga for any fixed time period but would not have a "long-term role" there.

New Zealand would have some role in rebuilding damaged infrastructure.

Dr Cullen told Newstalk ZB that Tonga had to move down the path towards democracy "otherwise I don't see how we can be there for any extended period at all".

His personal view was that there had to be a clear understanding that the path to democracy was strictly adhered to in order to get that help.

The violence was triggered by anger that Tonga's Parliament might finish this year's session without settling plans to introduce reforms that would give democratically elected lawmakers a parliamentary majority over royally appointed legislators.

The government had agreed on Tuesday to a plan ensuring that 21 lawmakers in the 30-seat Parliament will be elected starting in 2008 -- but it came too late to prevent the rioting.

Australians fleeing Tonga's deadly rioting have expressed relief at leaving the Pacific kingdom but hold grave concerns for its future.

An Australian RAAF jet carrying 49 people, including 36 Australians, touched down in Sydney last night.

The evacuees include foreign nationals from Britain, Papua New Guinea, Canada and the United States, along with one Tongan who is a permanent resident of Australia.

Ese Kava and her three children Liana, Lachlan and Jeremy, were among the Australian evacuees.

Ms Kava's real estate business was destroyed in the riots, and her husband Sam, a Tongan citizen, was forced to stay behind in Tonga.

"My business burnt down, we were situated next door to the target family so they burnt them first and that's how we got burnt," she told reporters at Sydney airport.

"It's all gone."

Ms Kava said she could not see herself returning to Tonga anytime in the near future.

"It's a peaceful country but they have destroyed it," she said.

"It's a small economy and it will be hard to recover."

Rioting broke out in the capital Nuku'alofa on Thursday, leaving at least eight people dead and destroying much of the city's business district.

Sydney woman Winnie Mujunen was visiting the Tongan capital for her son Andrew's 16th birthday when the rioting broke out.

She said she never thought the scenes they witnessed would occur in Tonga.

"It's so great to be back with the rest of the family," Ms Mujunen said.

"This is so out of character, I don't think anybody expected it."

Canadian evacuee Sharon Simpson said Tonga was now a mess, with no power, and much of the central business district would have to be rebuilt.

She said she felt for the "beautiful people" of Tonga who would be severely affected by the riots.

Australian and New Zealand troops have secured the airport since arriving on Saturday and the capital remained yesterday.

Tonga's government has maintained a state of emergency since pro-democracy demonstrations degenerated into looting and burning of shops and businesses.

Authorities reportedly have taken more than 100 people into custody over the violence.

Australia's Foreign Affairs Minister Alexander Downer and New Zealand Prime Minister Helen Clark said commercial flights in and out of Tonga should resume today.

- NZPA, AAP, NZHERALD STAFF