Lee Jae-myung, who leads South Korea's opposition party, was stabbed in the neck, and the entire thing was caught on camera. 

In the video, Jae-myung is seen answering questions from reporters while visiting the city of Busan to observe an airport building project. Suddenly, a man makes his way through the crowd and stabs the political leader in the neck. A scuffle ensues as the attacker is brought to the ground by what looks like security forces.

It was not immediately clear what caused the attack, though the assailant was confirmed to have been detained. Recent reports have indicated internal divisions inside South Korea's Democratic Party, with calls for Jae-myung to resign his position. 

This is a developing story.