The head of South Korea’s ruling Democratic Party, Song Young-gil, was attacked with a hammer Monday while campaigning just two days ahead of a contentious presidential election.

Video footage posted to social media showed an elderly attacker dressed in traditional Korean garb approaching Song from behind and striking him several times in the head with an object in a plastic bag, later revealed to be a hammer. He was quickly restrained by bystanders and detained by police.

Song, who was campaigning in Seoul for candidate Lee Jae-myung when the assault occurred, was taken to a hospital but was not seriously injured. He received stitches and was released.