Brazilian presidential candidate Jair Bolsonaro is in grave condition after being hospitalized for a stab wound, local media reported on Thursday.
Videos posted online showed Bolsonaro was being carried on his supporters' shoulders in a large crowd, when someone quickly stabbed him in the abdomen. Bolsonaro was then carried to safety, but appeared to be unconscious.
Police promptly arrested the suspect identified as 40-year-old Adelio Bispo de Oliveira, who was immediately grabbed by Bolsonaro's supporters.
There were conflicting reports as to the seriousness of the injury.
National news network Globo reported Bolsonaro required emergency surgery, while his son, Flavio, a candidate for the Brazilian senate, originally said on Twitter that his father's wounds were "only superficial."
Flavio has since called on supporters to pray for his father.
"Unfortunately it was more serious than we had expected. The perforation reached the liver, lungs and intestines. He lost a lot of blood, arrived at the hospital ... almost died. His condition now seems stabilized," he said.
Brazilian President Michel Temer described the attack as "intolerable."