Brazilian presidential candidate Jair Bolsonaro, the frontrunner in October elections, was stabbed during a campaign rally in southeastern Brazil on Thursday, local media outlets reported. He was in stable condition at a hospital, according to his family and local news reports.

Cellphone footage released by Brazilian media showed the candidate sitting on a supporter’s shoulders and waving to the crowd when someone plunged a knife into his abdomen. He was carried by his supporters to a car, grimacing and clutching his side. A 40-year-old man identified as the perpetrator was beaten by the crowd, police said. He was arrested and confessed to the crime, according to news reports.

Bolsonaro’s son Flavio tweeted that his father’s wound was “graver than we expected” and that he arrived at the hospital “nearly dead.” But he said that his father later appeared to be in stable condition. Hospital officials said the candidate suffered a serious wound to his intestine and was undergoing surgery, according to news reports.

The stabbing marks the second violent episode at an electoral rally during the presidential campaign. In May, several bullets struck busses in a caravan of supporters of former president Luiz Inácio Lula da Silva. Nobody was hurt.

The election campaign has been the most contentious in recent history. Last week, Brazil’s electoral court barred Lula from running due to corruption charges. The former president had been campaigning from behind bars.

“This reveals something that we need to be attuned to. The intolerance that has existed in Brazilian society is unacceptable,” said Brazilian President Michel Temer.

Bolsonaro is running on a tough-on-crime platform and has advocated for looser restrictions on gun ownership in Brazil.

With Lula out of the picture, Bolsonaro looks set to win the first round of the election on Oct. 7, but appears unlikely to capture enough votes to avoid a runoff. A right-wing former soldier, Bolsonaro now tops the polls with about 22 percent of those surveyed. Yet the candidate also carries the highest unfavorable ratings in the race.

Democracy is falling out of favor with many Brazilians who are fed up with corrupt politicians and rising violence. Some see in Bolsonaro a way to implement the order and discipline of Brazil’s military dictatorship, which ended in 1985 after two decades.

“ I think an event like this wouldn’t likely happen if we weren’t seeing a degree of radicalization in the public dialogue in Brazil,” said Claudio Couto, a political science professor at the Getulio Vargas Foundation, a university in Sao Paulo.