Large farm owners in Brazil are forming private militias to attack land rights campaigners, Human Rights Watch said on Thursday, as rural violence in Latin America's largest country hits its worst levels in a decade.

At least 54 people were killed in rural land conflicts in Brazil in 2016, said a Human Rights Watch (HRW) campaigner, citing the Pastoral Land Commission (CPT), a Brazilian organization linked the Catholic Church.

This is highest level of rural bloodshed in Brazil since 2003 when 71 people were murdered, the CPT said.