Police have in custody a man who allegedly assaulted chief of Jongno Police Station Park Geon-chan. According to the police, the assailant, identified by his surname Kim, assaulted Park on Sunday during a demonstration protesting against the Korea-U.S. Free Trade Agreement, resulting in injuries requiring three weeks of treatment to full recovery. Anti-FTA demonstrations flared up after the ruling Grand National Party ratified the deal unilaterally last Tuesday.

Kim was identified from CCTV footage and arrested at his home in Gyeonggi Province. He had been investigated by the police in August for throwing a water bottle at former U.S. Ambassador to Korea Kathleen Stephens’ vehicle.

The police plan to file for a warrant to detain Kim, and are now searching for others who assaulted Park.

Park was assaulted by around 100 protesters in the Gwanghwamun area around 9:30 p.m. Saturday.

According to Jongro station officers, the insignia from Park’s uniform were torn and his glasses broken during the assault.

“I feel devastated that I was attacked when I was trying to put an end to these illegal activities that can’t be overlooked,” Park said, referring to the anti-FTA protests. “I will make sure to penalize illegal actions in accordance with judicial procedures,” Park was quoted as saying by a local news agency after the incident.

“I was engaging in proper police activity and there was no reason for me not to don the uniform,” he said. “I didn’t expect such violence.”

The incident has prompted the police to take a sterner stance against protesters.

“The organization and leaders behind illegal, violent demonstrations that occupy roads or assaulting police officers will be held responsible,” Seoul Metropolitan Police Agency commissioner Lee Kang-deok said.

“Not only the assailants and the participants in the illegal protests, but also the organizers will be held responsible.”

By Choi He-suk (cheesuk@heraldcorp.com)