South Korean opposition leader and former presidential candidate Lee Jae-myung was attacked during a visit to the southeastern port city of Busan, according to South Korean media reports.

Lee was stabbed in the left side of the neck by an unknown assailant while speaking with reporters early Tuesday at the construction site of a new airport, according to South Korean media reports.

Lee was conscious but bleeding, according to South Korean media reports. Pictures showed him lying on the ground, with his eyes closed and mouth open, while those around him applied pressure to his neck.

The attacker was arrested at the scene, according to media reports. There is no word on a motive.

Lee is the head of South Korea’s main opposition Democratic Party. A liberal, Lee narrowly lost a 2022 presidential vote to conservative South Korean President Yoon Suk Yeol.

The 59-year-old is a polarizing figure in South Korean politics. In September, he ended a 24-day hunger strike to protest what he saw as the failed policies of his rival, Yoon.

Last year, South Korean prosecutors indicted Lee on corruption-related charges, including those related to a property development scandal. He avoided jail after a court rejected a warrant for his arrest.

Lee is known for his populist policies. As a former mayor of Gyeonggi, South Korea’s most populous province that surrounds Seoul, Lee advocated a form of universal basic income, in which citizens were to receive regular payments of money from the government.