The Brazilian government plans to send members of a military-style police unit to the border town of Pacaraima after residents there attacked Venezuelan migrants.

Government-run news agency Agencia Brasil said Sunday that the Public Security Ministry plans to send at least 60 members of the elite, military-style National Force to Pacaraima. Calls to the ministry for details went unanswered.

Pacaraima is a major border crossing with Venezuela, where economic and political turmoil has driven tens of thousands to cross into Brazil over the past few years.

Authorities have said that Saturday's violence erupted after a local store owner was robbed, stabbed and beaten in an assault blamed on four migrants.

Groups of angry residents then roamed the town hurling rocks at the immigrants and setting fire to their belongings.

'Humanitarian drama'

The army's Humanitarian Logistics Task Force in Roraima said Sunday that at least 1,200 immigrants fled Pacaraima to escape the violence and returned to Venezuela.

The Roraima state government estimates that more than 50,000 Venezuelan refugees have crossed the border, occupying already existing shelters or sleeping in tents, plazas and streets. The influx was nearly equal to 10 per cent of the state's population of 520,000 inhabitants.

Venezuelan children receive bread from a man at a bus terminal after being expelled from Pacaraima. (Nacho Doce/Reuters)

On Saturday, Claudio Lamachia, president of the Brazilian Bar Association, said that the violence in Pacaraima "exposed the humanitarian drama afflicting our neighbours … who are trying to improve their lives and survive."

"The state of Roraima does not have the conditions to shelter all the immigrants," he said.

The crisis has prompted state authorities in recent months to try to limit services to Venezuelans and temporarily shut the border. The federal government and high courts have curtailed attempts to do those things.