By Paulo Cabral
BBC Brasil, Santarem
Father Henri has had bodyguards since 2005
Father Henri de Roziers has worked to help the poor and landless in the Amazon for more than 30 years.
But as the Dominican priest goes about his business in the Brazilian state of Para, he is guarded around the clock by three police officers.
"Discussing land issues is extremely dangerous in Para. There is a mafia of farmers and loggers who still solve all their problems by shooting," says French-born Father Henri.
Violence in the Amazon was brought to the world's attention in February 2005 when American nun and land rights activist Dorothy Stang was killed in the city of Anapu in Para.
Police investigating her murder discovered that Father Henri was next on the killers' list.
Since then he has had bodyguards. State authorities have also set up a programme to offer protection to other threatened activists.
Culture of violence
It seems such protection is badly needed. A survey from the Catholic Church's Pastoral Land Commission (CPT) documented 20 killings in 2008 linked to land issues in the Amazon, accounting for three-quarters of such murders across Brazil.
In the past few years there has been a clear strengthening of law enforcement in the region. But the decades when government was virtually absent have created a culture of violence to sort out any kinds of conflicts, whether over land, water, labour, money or even personal issues.
"Even though the overall number of conflicts has been reduced, the level of violence has increased," the CPT report found. "In 2007, there was one killing in every 54 conflicts. Last year this ratio was 1 to 42 conflicts."
Land disputes are seen as one of the greatest challenges the Brazilian government faces in putting illegal occupations occupations of land in the Amazon on a regular footing.
Activists and farmers' organisations fear that small farmers will be pressured to informally sell their areas to big landowners - the "latifundiarios" - who would then use frontmen to register all the land under a new official regularisation scheme.
Indigenous leader Dada Borari wants his people's land properly marked
Ubiratan Cazetta, the federal prosecutor of Para, says this would be one of the strategies to bypass the 1,500 hectare limit imposed by the law to acquire land ownership.
"We have to deal with people who live in remote and isolated areas. Many aren't even aware that they also have rights. It's just too easy for big farmers to prey on these people," says Mr Cazetta.
Officials, however, say that any sign of dispute will be enough to bar the regularisation of any farm.
"We will check all larger properties before granting property rights and so we will know if there is any conflict in the area," says the chairman of the official land institute of Para, Heder Benatti.
But there still is also a lot of uncertainty regarding land claimed by traditional communities, such as indigenous people and fishing villagers along the Amazon rivers.
The Brazilian constitution says that these groups have priority in land ownership but establishing their boundaries demands complex historical and anthropological research that, in many cases, is still to be conducted.
Art. 231: Indigenous people are entitled to their social organisation, costumes, languages, beliefs and traditions, and to the native rights over the land they have traditionally occupied. It is the task of the state to establish its boundaries, to protect it and enforce strict respect to all of its assets
Land traditionally occupied by indigenous people is destined to their permanent possession and their exclusive use of the resources from the soil, the rivers and the lakes
One good example is that of the Nova Olinda area, in the south of Para.
Farmers and loggers were relocated there when an area they had legally received from the regional government in the 1970s was given over to an indigenous community years later.
The problem is that now indigenous tribes are also claiming Nova Olinda. As the case is still being examined, everything has been frozen - except the violence.
"I was caught by farmers who kept me tied in the forest for many hours threatening to kill me. They wanted me to drop the fight for our ancestors' land, but I won't," says cacique (tribal chief) Dada Borari.
He is calling on the government to establish the exact boundaries of their territory so they will have legal rights to occupy it.
"The constitution states clearly that our land has priority. All we ask for is the law to be obeyed," he says.
State authorities in Para also complain that it is impossible to administer land issues while the federal government does not stipulate what land can or cannot be used for farming.
"We certainly do not want to disrespect Indian territory - we just need to know where it is," says Girolamo Treccani from the Land Institute of Para.