Gunmen have attacked a prison in northern Brazil trying to stage a mass escape of inmates, setting off a gun battle with police that killed 20 people and injured at least four, authorities said.

Former Brazilian president Luiz Inacio Lula da Silva has been taken into police custody after a tense showdown with his own supporters.

Former Brazilian president Luiz Inacio Lula da Silva has told thousands of supporters that he will turn himself in to police.

Former Brazilian President Luiz Inacio Lula da Silva has defied an order to turn himself in to police as he hunkered down with supporters at a metallurgical union that was the spiritual birthplace of his rise to power.

Brazilian protesters and police clashed near a stadium hosting a football match, as thousands of demonstrators trying to march on the site were met by tear gas and rubber bullets.