Pro-Tibetan protesters beamed laser signs onto the Sydney Harbour Bridge on Wednesday reading "Don't Torch Tibet" and "China, talk to the Dalai Lama", as the Olympic torch arrived in Australia under tight security.

A group of Tibetans who were on a hunger strike continued their 70 km (43 miles) march to Canberra to rally against the torch as it landed at an airforce base in the capital under security usually afforded visiting world leaders.

Thousands of pro-Tibet supporters have promised to hold a peaceful rally during Thursday's torch relay in Canberra, but thousands of Chinese students were also expected to rally to support China.

Media reports said the Chinese embassy had hired 20 buses to bring supporters from Sydney and the southern city of Melbourne, an eight-hour drive from Canberra, to counter protesters.

"We're in a democratic country. If people want to protest, that's a matter for them, as long as they do it peacefully," International Olympic spokesman Kevin Gosper told Reuters after watching the Olympic torch arrive.

Hundreds of extra police have been called in to protect the torch, which will be carried through closed-off and barricaded streets on Thursday, with authorities determined to avoid the chaos that disrupted the relay in Europe and the United States.

China had hoped the torch's journey would be a symbol of unity in the run-up to the Beijing Games, but the torch has drawn anti-China protests over human rights and Beijing's crackdown in Tibet, as well as pro-China demonstrations.

Aborigine Bunja Smith, who presented Chinese torch officials in Canberra with a traditional wooden message stick inscribed with the word "Peace", said Australia's Aborigines had a long history of repression and understood the need for protest.

"I believe in human rights ... (but) you can't give someone human rights by taking away someone else's human rights," Smith told Reuters.

"We are a people who have been repressed, but we ask the protesters to keep it a protest and not violent," he said.

"It's the Chinese people's right to have the Olympics. That's how we are looking at it - in the spirit of sport."

Relay organiser Ted Quinlan said he did not expect clashes, while a spokeswoman for China's Foreign Ministry said on Tuesday she was confident the Canberra torch relay would be a success.

"I'm convinced that these elements of meddling and sabotage don't represent the Australian people. Their acts of sabotage will not succeed," said spokeswoman Jiang Yu.

Tibet supporters tried to disrupt the torch lighting ceremony in Greece in March, and disrupted the relay in London, Paris and San Francisco, prompting officials to boost security and shorten the torch relay in India, Malaysia and Indonesia.

On Tuesday, China cancelled media access to the departure of a second torch from Everest North Base Camp before an attempt to take it to the top of the world's highest mountain. Officials denied the cancellation was linked to unrest in Tibetan areas.

Australian organisers have dropped plans to run the torch past the Chinese embassy, near Australia's national parliament, fearing the embassy could become a flashpoint for protests.