Sergeant Chris Meagher, of ACT Policing, said no one was injured in the scuffles and it was unlikely any arrests would be made.

Police had been liaising with indigenous elders at the tent embassy throughout the day, with a peaceful protest march of about 1500 taking place earlier on Thursday.

Sgt Meagher said the protest had been a move by those at the tent embassy to get their point across.

"Basically, there was a minor fracas between ourselves and the demonstrators," he told reporters.

"We believe in being quite flexible in our policing actions with these people, and they've had a point to prove today and they're having their celebrations.

"We have no intention of arresting anybody for no unreasonable cause."

Some protesters said they would spread the word via social media and get more people to the area for further protests on Friday.

Prime Minister Julia Gillard and Opposition Leader Tony Abbott were forced to run a gauntlet of Aboriginal protesters after violent scenes marred an Australia Day medal ceremony.

About 200 protesters trapped Ms Gillard and Mr Abbott in a Canberra restaurant, where they were attending the inaugural national emergency medals ceremony, before police arrived to clear a passage for the pair.

The protesters, from the nearby Aboriginal tent embassy, banged on the three glass walls of The Lobby restaurant chanting "shame" and "racist".

On a day that many Aboriginal people consider "invasion day", they had taken offence at comments by Mr Abbott that the embassy may have reached its used-by date.

The embassy celebrates its 40-year anniversary on Friday and thousands of indigenous Australians have travelled to Canberra for a three-day "Corroboree for Sovereignty".

About 50 police, including the riot squad, were called to The Lobby shortly after 2.30pm (AEDT).

While trapped inside the restaurant, The Nine Network recorded Ms Gillard expressing her concern for Mr Abbott's safety.

"Okay, what about Mr Abbott? Where have you got him? We'd better help him through too, hadn't we?" she told her security guard when he informed her it wasn't safe to stay much longer.

Meeting up with Ms Gillard, Mr Abbott said he was concerned the glass windows would be smashed and asked when they would leave.

"They'll let us know. We'll just pull together," Ms Gillard reassured him.

The two leaders, protected by police and security officers, escaped out a side door after almost 20 minutes.

Ms Gillard stumbled and lost a navy-blue suede wedge shoe while running to her car.

The protesters later collected the shoe and proclaimed it as a trophy.

On the tent embassy's Facebook page there is a picture of Ms Gillard losing her shoe with the caption:

"What is losing a shoe compared to losing an entire continent?"

On Thursday morning Mr Abbott had said he understood why the tent embassy was set up "all those years ago".

"I think a lot has changed for the better since then," he told reporters in Sydney.

"I think the indigenous people of Australia can be very proud of the respect in which they are held by every Australian.

"I think a lot has changed since then, and I think it probably is time to move on from that."

Embassy founder Michael Anderson said the opposition leader's comments were disrespectful.

"Abbott said the Aboriginal embassy had to go. We heard it on a radio broadcast," he told AAP.

"We thought no way, so we circled around the building."

He said the protesters wanted the leaders to clarify their position and to know whether Mr Abbott was serious about removing the embassy.

"It's just madness on the part of Tony Abbott," Mr Anderson said.

"What he said amounts to inciting racial riots."

~~~

These people should be in jail, but not before the bulldozers clear the site where some have set up a tent.

Embassy, ha ha ha.