Opposition leader Lee Jae-myung is transferred to a hospital after he was stabbed in the neck during a visit to the southeastern port city of Busan, Jan. 2. Newsis

Opposition leader Lee Jae-myung was stabbed in the neck during a visit to the southeastern port city of Busan on Tuesday and was airlifted to Seoul for surgery amid fears of additional bleeding, though the wound is not life-threatening, officials said.

Lee, the chairman of the main opposition Democratic Party of Korea (DPK), was stabbed on the left side of his neck by an unidentified man at 10:27 a.m. after touring the construction site of a new airport on Busan's Gadeok Island.

Lee was promptly transported to Pusan National University Hospital while conscious and underwent emergency treatment for a laceration of approximately 1 centimeter in his neck, according to fire authorities.

Lee was then airlifted to Seoul National University Hospital for surgery, they said.

The DPK said there are concerns about potential massive bleeding around Lee's jugular vein.

Lee Jae-myung, leader of the main opposition Democratic Party of Korea, is attended to by his aides after being attacked by a man brandishing a knife during a visit to the construction site of an airport on Gadeok Island off the southeastern port city of Busan, Jan. 2. Yonhap

Eyewitnesses recount that the male suspect, appeared to be in his 60s or 70s, approached the politician under the guise of a supporter, requesting an autograph amid a crowd of supporters and reporters.

The assailant then proceeded to carry out the attack with an unidentified weapon measuring approximately 20-30 centimeters in length.

The suspect was arrested at the scene and hauled away by police.

He has maintained his silence regarding both his identity and motive, according to police officers.

The suspect was also found to have been around the site of an event Lee attended in Busan last month.

Video footage uploaded on YouTube shows the suspect waiting for Lee in the crowd but being unable to make close contact. The suspect was wearing the same paper crown with the words "I'm Lee Jae-myung" as he did Tuesday.

President Yoon Suk Yeol expressed deep concern over Lee's safety, and ordered the police and relevant authorities to swiftly determine the facts and make every effort to quickly transport Lee to a hospital and provide him with treatment, according to his spokesperson Kim Soo-kyung.

Yoon also stressed that such violence should never be tolerated under any circumstances, Kim said.

Opposition leader Lee Jae-myung is transferred to Seoul National University Hostpital via helicopter, Jan. 2. Yonhap

The DPK condemned the attack on its leader, categorizing it as an act of terror and a threat to democracy.

"This should never have happened under any circumstances," the DPK's chief spokesperson, Rep. Kwon Chil-seung, told reporters in front of the hospital.

The country's police chief announced the formation of a special investigation team in Busan to conduct a thorough and swift inquiry into the attack.

"Security protection for key personnel will be strengthened to prevent similar incidents from occurring," Yoon Hee-keun, the commissioner general of the National Police Agency, said in a press release.

Prosecutors also said they have formed a special investigation team to get to the bottom of the attack.(Yonhap)