There have been minor scuffles and scattered arrests as thousands of demonstrators watch the Olympic torch relay on its way through Canberra.

Two members of the controversial tracksuited Chinese guards ran with the torch as it made its way along the route, but Australian Federal Police (AFP) officers initially appeared to be shepherding them as far away from the torch as possible.

There had been confusion over the attendants' role in the run-up to the relay, with Prime Minister Kevin Rudd pledging that no Chinese personnel would be allowed to provide security and Olympic officials saying they would be on hand to act as "human shields" in the event of any trouble.

The AFP men later appeared to relent and allow the Chinese attendants to run alongside and assist with the handover of the torch between bearers.

There have been at least four arrests and one man was detained when he set fire to a Chinese flag, drawing angry protests from nearby pro-China demonstrators.

Another protester was dragged aside by AFP officers a few hundred metres from Parliament House after he threw himself on the ground ahead of a torchbearer.

Two pro-Tibet women charged the torch convoy as it neared Parliament House and were dragged away by police as one yelled:"They're torturing my country".

The thousands of Chinese protesters vastly outnumbered the pro-Tibetans, with Chinese flags dominating Reconciliation Place and the route of the relay.

Pro-China demonstrators waved flags and spelled out 'OneChina' in red on a lawn alongside the relay route.

Sky News reported that Parliament House had gone into lock-down during the relay.

But security has not been as tight as it has been on international legs of the relay, with just a small number of AFP officers running alongside each bearer.

Police were forced to intervene at the start of the relay when protesters on either side threw projectiles, including full water bottles, at each other.

As the torch started its journey in the hands of 2007 Young Australian of the Year Tania Major with a trip across Lake Burley Griffin in a rowboat, the words 'Free Tibet' were written across the sky by a skywriting plane.

Ms Major said the atmosphere at the start of the relay was overwhelming.

"I was actually a bit nervous and excited, given I had everyone in my face and screaming and the emotions around me and the security by my side," she said.

Earlier there was a traditional welcome to country ceremony and a cleansing and smoking ceremony from the local Aboriginal community.

Local Aboriginal elder Matilda House gave the traditional welcome to the relay.

"The eyes of the world are on us, on our country here today," she said. "To those of you, especially those who have travelled from afar, soak up this beauty, soak up this beautiful land."

Pro-Tibetan protesters say many of the Chinese demonstrators have been bussed in by the Chinese embassy.

The head of the Canberra torch relay committee admitted organisers were caught by surprise by organised Chinese support for the torch.

"We didn't expect this reaction from the Chinese community," committee head Ted Quinlan admitted.