High murder rates blight Brazil's indigenous communities
Doraci Claudio was sleeping when the police rang. They wanted her to help identify the remains of two young men believed to be her sons.
Devanildo and Ioracilmo had been found lying by the roadside, their bodies scarred by knife wounds.
Ms Claudio, a member of the Guarani Kaiowa indigenous group, believes her sons were killed by a gang while resisting a robbery.
Walking across Dourados, the village in Brazil's southern state of Mato Grosso do Sul where she lives, Ms Claudio recalls another phone call six years earlier.
That night, her son Vanilson was found dead with 25 machete wounds, thought to have been inflicted in a fight in a bar.
"It took me some time to learn that the pain of losing a son never ends", says Ms Claudio. "Then I found out I had lost another two."
The killings of the three brothers are just one indication of the shocking patterns of violence faced by native peoples in Brazil.
According to new figures from the Ministry of Health obtained by BBC Brasil, 833 indigenous people have been murdered in Brazil since 2007.
Sometimes the killings are the result of fights and tensions within the indigenous communities, other times they are the result of disputes with local landowners.
The situation is worst in Mato Grosso do Sul, which has Brazil's second largest indigenous population - about 73,000 people in total.
In 2013, the per capita homicide rate in the state's most populous indigenous reserve, Dourados, was higher than that of Maceio, Brazil's most violent city.
Analysts say the violence can be traced back to a century-old government policy aimed at expelling indigenous peoples from their lands to make way for large-scale farming.
Under the policy, which lasted until the end of Brazil's military dictatorship in the 1980s, indigenous families from disparate communities were moved to areas with limited space and resources.
These areas quickly became breeding grounds for conflicts and social problems, resulting in a marked rise in both homicides and suicides among local native peoples.
Living in fear
Ms Claudio thinks that the motive for her sons' killings was greed.
She recalls that one of them had just been paid his wages. "They even took his sandals and hat, and then left him naked by the road, like a dead dog."
She believes the killers are from her own community, and says that three of them still live in her village. They have never been detained, she says.
Ms Claudio now fears for the two other sons who still live with her.
"I can't even send them to the market. If I do, they might kill them just like they killed their brothers," she says.
Dourados police chief Lupercio Degerone Lucio insists that the police investigate all the homicides in indigenous villages in the region and that dozens of people have been convicted for crimes there.
He says in the case of Ms Claudio's sons, arrests were made but some of the suspects had to be released because of a lack of evidence.
The police chief blames drug and alcohol abuse for the community's high murder rate. The sale of alcohol in indigenous areas is banned under Brazilian law, but he says the rule is hard to enforce.
"Many villages are close to the city and there are many ways of entering them," he explains.
According to Guarani Kaiowa leader Getulio Juca, locals are turning to vigilantism because crimes in the community are not being properly investigated by officials.
"When a family sees the police are unable to arrest the man who killed their son, they decide to take justice into their own hands", he says.
"This has created cycles of revenge among local families."
He says some in the indigenous community are calling for the creation of a indigenous security force to police the reserve.
But many indigenous people believe a permanent solution to the violence requires their communities to be granted more land.
Following an influx of non-indigenous settlers into the region over the past century, the indigenous areas in Mato Grosso do Sul are much smaller than similar reserves in the Amazon region.
Some indigenous groups have decided to up sticks and leave the poor and often violent conditions in their reserves.
In the past decades, more and more have been laying claim to what they say is their ancestral territory.
Some have occupied farmlands, which has put them at loggerheads with landowners.
Under Brazil's constitution, indigenous groups have the right to return to the lands they were expelled from.
But in order to do so they have to be backed up by government studies that prove their historical ties to the land - a process which takes time.
If the study goes in the indigenous group's favour, the farmers have to be expelled from the land, which many resist. A lengthy legal battle often ensues.
Meanwhile, Mr Juca says that his people are being "massacred".
"We want to live in peace on our ancestors' lands, but we need the authorities to act now," he says.