Some 300 indigenous protesters tried to force their way into Brazil's Congress on Wednesday to demand respect of their land rights but were thwarted by police.
Police tightened security around the legislature and even used pepper spray as the natives, adorned with feathers and traditional garb and carrying spears and arrows, raced to try to get inside.
"There were about 300 indigenous people in the protests outside Congress. They tried to break in but were stopped by police who had to use pepper spray," a military spokesman told AFP.
The natives later regrouped near the Congress building and blocked traffic.
Hundreds of native Indians from across the country traveled to Brasilia this week to protest against bills that they say would jeopardize recognition of their ancestral lands to the benefit of powerful white landowners.
Indigenous people represent one percent of Brazil's more than 200 million-strong population and occupy 12 percent of the national territory, mainly in the Amazon.
They are frequently locked in bitter land feuds with wealthy ranchers, who control 46 percent of the cultivated land.
The militants said they planned more protests in other Brazilian cities and even abroad.
London-based Survival International, an advocate of natives' rights, said an indigenous Brazilian official led a protest outside the Brazilian embassy in the British capital Wednesday.