SEOUL, South Korea — South Korean opposition leader Lee Jae-myung was attacked and injured by an unidentified man during a visit Tuesday to the southeastern city of Busan, emergency officials said.

Busan's emergency office said Lee was attacked as he visited the construction site of a new airport in the city.

It said Lee, head of the main opposition Democratic Party, was conscious but his exact condition was unknown.

South Korean media cited witnesses as saying the man used a knife-like weapon to stab Lee's neck. TV video showed Lee lying on the ground with a person pressing a handkerchief to his neck to stop the bleeding.

The reports said police arrested the man on the spot. They said the attacker was wearing something that looked like a crown on his head.

Lee lost the 2022 presidential election to President Yoon Suk Yeol by a narrow margin.

Lee, a liberal former provincial governor, is known for his outspoken style. His supporters see him as an anti-elitist hero who could reform establishment politics, eradicate corruption and solve growing economic inequality. Critics view him as a dangerous populist who relies on stoking divisions and demonizing his conservative opponents.