Sao Paulo, Brazil – Thousands of indigenous Brazilians from across the country have rallied in the capital, Brasilia, to call authorities to protect their land rights.

Organisers of the annual “Free Land Camp” in Brasilia said more than 3,000 people reached the city this week to denounce what advocacy groups say is a continuing and unprecedented rollback of indigenous rights in the country.

“We are here to demand our rights,” Jailson dos Santos, leader of the Kariri-Xoko tribe from Bahia, northeastern Brazil, told Al Jazeera from the protest outside the attorney general’s office on Wednesday.

Indigenous people’s right to their traditional lands is enshrined in Brazil‘s constitution. In practice, however, this right is rarely respected and their lands are often targeted by loggers, land grabbers and wildcat miners.

Since last year, experts say, an already dire situation got considerably worse with increased invasions of indigenous territories, anti-indigenous measures pushed by Brazil’s powerful farming lobby and cuts to indigenous protection agencies.

‘Violent land grabbing’

“What we are seeing now is new phase of violent land grabbing and occupation of indigenous territories that are already demarcated,” Cleber Buzatto, executive-secretary of Brazil’s Indigenous Missionary Council (CIMI) told Al Jazeera.

Last May, more than a dozen members of the Gamela tribe in Maranhao state were hospitalised after a vicious attack with guns and machetes by local ranchers.

In September, Al Jazeera reported that prosecutors were investigating the massacre of an “uncontacted” indigenous tribe in a far-flung part of Brazil’s Amazon near the border with Peru.

Last week, Adriano Karipuna, member and spokesman of the Karipuna tribe from the northwestern state of Rondonia state, went to the United Nations in New York to denounce violations against his tribe that Brazil prosecutors say is on the verge of “genocide”.

“We asked for support of the world that the Brazilian government be responsible for removing all of the invaders from our land that are logging, land grabbing and mining,” Karipuna told Al Jazeera.

Greenpeace’s investigative journalism unit, Unearthed, visited the Karipuna territory last year and documented the devastating effect of encroaching loggers and land grabbers.

Last week, Al Jazeera reported that killings over land and resources had peaked to their highest number since 2003. On Wednesday, the United Nations environmental officeissued a statement condemning the violence.

Indigenous legal protections under threat

Indigenous demarcations, the process by which indigenous people gain legal protections to their lands, are frozen and under threat of being rolled back even further, Buzatto, of CIMI, said.

Buzatto blamed the introduction of a legal ruling known as “marco temporal”, the focus of the Brasilia protest, which stipulates that indigenous people can only live on their lands if they occupied them before Brazil’s post-dictatorship constitution of 1998, as reported by Al Jazeera last year.

“This increases the potential conflicts inside indigenous territories,” Buzatto added, “as it gives a kind of protection to illegal acts committed against indigenous people”.

Proponents of the ruling in Brazil’s agricultural caucus in Congress say that it gives protection to small landowners from indigenous demarcations.

In total, according to CIMI, there are at least 33 proposed projects in motion in Congress that seek to weaken indigenous rights, including the transfer of demarcation power to Brazil’s parliament which is dominated by agricultural interests and proposals to open up indigenous territories to mining.

Brazil’s National Indigenous Foundation (FUNAI), which is tasked with guaranteeing the protection of indigenous rights, has also been the target of heavy cuts and a parliamentary commission inquiry led Brazil’s agricultural caucus in Congress.

This week, it was reported that FUNAI’s president was changed after pressure by the agriculture caucus.

Brazil is home to roughly 900,000 indigenous people of more than 200 tribes, the majority of whom live in the country’s nine Amazon states.

Between 1964 and 1985, during Brazil’s military dictatorship, more than 8,000 indigenous people were killed, according to the National Truth Commission, which was set up to investigate human rights violations during the 1946-1988 period.