The suspect in the stabbing attack against opposition leader Lee Jae-myung was formally arrested Thursday on charges of attempted murder.

The Busan District Court issued an arrest warrant for the 67-year-old assailant, surnamed Kim, citing the risk of him fleeing. The warrant, which was issued just two hours after the court's arraignment of him, allows the police to continue holding the suspect, who was detained at the scene.

Lee, the chairman of the main opposition Democratic Party (DP), was stabbed in the neck with a camping knife by Kim who posed as an autograph seeker Tuesday morning during Lee's public event in the southeastern port city of Busan.

Meanwhile, a surgeon who operated on the politician said he is smoothly recovering following surgery to repair a major vein in his neck.

"Lee is recovering smoothly but requires continued observation due to concerns over additional infection and post-surgery complications due to the injury he suffered," Min Seung-kee from Seoul National University Hospital told a news press briefing.

The professor, who is in the hospital's vascular surgery unit, mentioned that Lee had a wound about 1.4 centimeters in length but was fortunate not to suffer any damage to the artery, surrounding cerebral nerve or airway.

Min also said it is customary for the patient to stay in the intensive care unit first, as vein reconstruction can lead to more bleeding or other complications, such as blood clots. Lee is now in a general ward.

While his motive remains unknown, Kim confessed to intending to kill Lee and admitted that he had plotted the attack alone.

The police investigation has also shown that the suspect followed Lee six times since last June, and purchased a 17-centimeter camping knife and modified it for the attack.

When asked about his motive by reporters before attending a court hearing to decide on his warrant, Kim said that he had submitted an eight-page note explaining his reasons to the police. (Yonhap)