Activists want to protect land that is being cleared for pasture

A Brazilian land reform activist has been killed in the Amazon state of Para amid ongoing land disputes in the area.

Police said two men on motorbikes shot Pedro Alcantara de Souza five times in the head as he was riding a bicycle.

Mr Souza, the head of a union of landless farmers in Para, had led the occupations of large farms by peasants.

American nun Dorothy Stang was killed in the same region in 2005, after she had spent three decades working with peasants and small farmers there.

Contract killings

Mr Souza was the president of the small farmers' union in the town of Rendencao and had previously served for 14 years as the city councillor.

The police say his killing was carried out by hired gunmen, the BBC's Paulo Cabral reports From Sao Paulo.

No arrests have yet been made.

Mr Souza was shot just hours after the trial was delayed of the landowner accused of ordering the murder of Dorothy Stang, 73.

Vitalmiro Bastos Moura was originally convicted for the killing in 2007. The verdict was overturned a year later, but he is now due to face a third trial.

There were 20 documented killings in 2008 linked to land issues in the Amazon, a survey by the Catholic Church showed.

Brazil's agrarian reform laws state that unused farmland can be taken by the government and distributed among landless farmers.

There have been some improvements in recent years, but severe inequality persists - government figures show that nearly half the arable land in Brazil belongs to just 1% of the population.