Sydney (CNN) -- Security officers dragged Australian Prime Minister Julia Gillard out of a Canberra restaurant Thursday after an angry mob of protesters surrounded the building during a luncheon ceremony, police said.
Gillard and federal opposition leader Tony Abbott were taken out of the building after a group of between 50 and 100 protesters from a nearby ceremony gathered around the building, bashing windows and brandishing sticks and rocks, according to federal police.
The prime minister was presenting medals to emergency service workers during an Australia Day celebration. In a nearby venue, a spontaneous protest erupted with an Aboriginal rights group. The group was commemorating the 40th anniversary of an Aboriginal "tent embassy."
The Australian Broadcasting Corporation (ABC) reported the protesters were chanting "shame" and "racist" as they banged on the restaurant's three glass sides.
Gillard and Abbott were taken out a side door, the ABC said. At least 50 police were called to help escort them from the restaurant.
Local media reported Gillard was visibly shaken, and stumbled during the encounter.
Photographs showed her being dragged to a waiting vehicle by a group of at least seven security officers, losing a shoe in the process.
Video showed her being hustled into the vehicle, surrounded by security officers, some carrying shields, as protesters shouted, "Shame on you."
The shoe was collected by protesters, who proclaimed it a trophy. On the tent embassy's Facebook page, according to the ABC, there was a picture of Gillard losing her shoe with the caption: "What is losing a shoe compared to losing an entire continent?"
Australia's Nine Network captured the conversation inside the restaurant as the two were being escorted out.
"OK, what about Mr. Abbott? Have you got him? We'd better help him through too, hadn't we?" Gillard asks her security guard after he told her it was not safe to stay much longer.
There were no injuries, and no arrests were made, Australian Federal Police said. Video from the ABC showed some minor struggles breaking out between authorities and protesters.
As Gillard and Abbott left, the protesters chased her vehicle down the street, banging on its roof, the broadcasting corporation reported.
The protesters apparently were angry about remarks made by Abbott earlier Thursday, in which he suggested it may be time to reconsider the tent embassy's relevance.
The establishment of the embassy was a symbolic protest against then-Prime Minister Billy McMahon's refusal to acknowledge land rights for indigenous Australians, the ABC said. Over the years, it has been a controversial site and the scene of clashes, the broadcasting corporation said.
"I think the indigenous people of Australia can be very proud of the respect in which they are held by every Australian," Abbott said earlier Thursday, according to the ABC. "But I think a lot has changed since then and I think it probably is time to move on from that."
Activist Sean Gordon told the ABC, "We have no economic base for who we are as Aboriginal people. We have title to land we aren't able to do anything with. How have we moved on?'
Following the incident, Gillard put on a "brave face" as she held a function for international ambassadors, the ABC said.
"Oh, I'm fine, I'm fine," the prime minister told the network. "The only thing that really kind of angers me about it is that it disrupted such a wonderful event for great people, emergency services medals, just amazing people."
"I am made of pretty tough stuff and the police did a great job," she said.
Last week, an Australian panel suggested changes to the nation's constitution to give better recognition to indigenous Australians, often referred to as Aboriginal and Torres Strait Islander peoples.
The groups have suffered at the hands of later settlers and the government they established. Australian politicians have since apologized for the past mistreatment, but Aborigines remain disadvantaged socially and economically compared with the overall population.
Explicit references to Aborigines in the original Constitution, drafted in the late 19th century, were subsequently deemed to be negative. Australians voted overwhelmingly to remove those points in a 1967 referendum, but many people say the document can be further improved to acknowledge the role of the country's indigenous population.
The panel -- which included Aboriginal leaders, business executives, legal experts and members of the main political parties -- handed over its report to Gillard, whose government has promised to hold a referendum on the matter by the next general election.