Far-right firebrand Congressman Jair Bolsonaro, a controversial figure who has enraged many Brazilians for years with divisive comments, but has a devout following among conservative voters, could take two months to fully recover and will spend at least a week in the hospital, said Dr. Luiz Henrique Borsato, who operated on the candidate.

"His internal wounds were grave and put the patient's life at risk," Borsato said, adding that a serious challenge now would be preventing an infection that could be caused by the perforation of Bolsonaro's intestines.

The attack on Bolsonaro, 63, is a dramatic twist in what was already Brazil's most unpredictable election since the country's return to democracy three decades ago. Corruption investigations have jailed scores of powerful businessmen and politicians in recent years, and alienated infuriated voters.

There were fears that violence could flare across Brazil on Friday, as the nation celebrates its Independence Day and political groups are expected to march in hundreds of cities. Bolsonaro's rival candidates called off their campaign activities for Friday.

ELECTION IMPACT

Under Brazilian campaign laws, Bolsonaro's tiny coalition has almost no campaign time on government-regulated candidate ad blocs on TV and radio. That means he relies deeply on social media and raucous rallies around the country to drum up support. If Bolsonaro is not able to go out in the streets, it could jeopardize his campaign.

But Flavio Bolsonaro, the candidate's son, said early Friday outside the hospital where his father was treated that he was conscious and the attack was a political boost.