The protest lasted around two hours but intensified concerns over security at COP30 after a demonstration on Tuesday in which Indigenous activists stormed the conference venue.

On Friday, around 60 men and women in tribal garb and headdresses, some carrying babies, formed a human barricade at the main summit entrance as tens of thousands of delegates were arriving.

Dozens of armed soldiers and military police were guarding the venue entrance, but the United Nations said in a message to attendees that there was "no danger."

Beneath a blazing sun, the group demanded a meeting with Brazilian President Luiz Inacio Lula da Silva and stood their ground as diplomats were ushered through side doors into the venue.

"Come on, Lula, show yourself!" shouted Alessandra Korap, an Indigenous leader.

"We want to be heard, we also want to participate in the negotiations," she added. "We have too many problems."

COP30 president Andre Correa do Lago skipped a morning event to meet with the group, accepting the hand of one protester and at another point, holding a baby in a feathered headpiece.

The demonstrators had "strong and very legitimate concerns," said Correa do Lago after the consultations in a nearby hall where Indigenous people of all ages sang, danced and chanted.

"We had a very positive, very constructive dialogue," he said.

- 'Never heard' -

After a second intervention that lasted many hours, Correa do Lago said: "You can be sure that this government will defend you at COP30" and he denied there was any "threat" to their rights.

The protesters, from the Munduruku community, are seeking to advance the process of demarcating their traditional homelands.

They also contest the so-called Ferrograo project, a nearly 1,000 kilometer (620 mile) railway intended to cross Brazil from west to east to transport grain.

"Fighting for our territories is fighting for our lives," read a banner held by one Munduruku demonstrator.

Lula is a self-proclaimed ally of the Indigenous cause.

He has advanced recognition of tribal groups, cut deforestation in the Amazon and appointed a widely respected figure to head the first-ever Ministry of Indigenous Peoples.

But many deplore the slow pace of demarcating Indigenous lands and oil exploration launched in October near the mouth of the Amazon.

On Wednesday, the iconic Indigenous chief Raoni said he would "make an appointment" with Lula over the oil project and Ferrograo and "if necessary, I'll give him a good talking-to."

After about two hours, the thousands of attendees waiting outside in the sun were able to get into the venue through the main gate.

Brazil on Thursday defended security at COP30 after concerns were raised earlier this week over the previous demonstration.

On Tuesday evening, Indigenous protesters and their supporters stormed the negotiation venue and clashed with guards in scenes rarely witnessed at a UN climate conference.

When asked by AFP on Thursday about the possible need for additional security measures in Belem, Correa do Lago replied: "No need, it was really a minor incident."