South Korean opposition leader Lee Jae-myung was attacked and injured by a man during a visit to the south-eastern city of Busan on Tuesday, emergency officials said. The attack happened as Mr Lee walked through a crowd of journalists and others after a tour of the site of a new airport in Busan. The attacker approached Mr Lee, saying he wanted an autograph, and then stabbed him in the left of his neck with a knife, senior Busan police officer Sohn Jae-han said. Mr Sohn said Democratic Party officials near Mr Lee quickly subdued the attacker before police officers detained him. He said 41 officers were sent to the area for crowd control and traffic management. The suspect, aged about 67, told investigators that he bought the 18-centimetre knife online. Police were investigating the motive for the attack, Mr Sohn said. Other officers said police were expected to request that the suspect be formally arrested on an attempted murder charge because he told investigators he intended to kill Mr Lee. Mr Lee’s Democratic Party called the incident “a terrorist attack on Lee and a serious threat to democracy.” It called on police to make a through, swift investigation. At Pusan National University Hospital in Busan, where Mr Lee received emergency treatment, party representative Kwon Chil-seung said his jugular vein was believed to have been damaged and there was concern over the large amount of bleeding. Hospital officials would not comment on Mr Lee’s condition. President Yoon Suk Yeol expressed deep concern about Mr Lee’s health and ordered authorities to investigate the attack, saying such violence would not be tolerated. Mr Lee lost the 2022 presidential election to President Yoon Suk Yeol by a narrow margin. Mr Lee, a liberal former provincial governor, is known for his outspoken style. His supporters regard him as an anti-elitist hero who could reform establishment politics, eradicate corruption and solve growing economic inequality. Critics view him as a populist who relies on stoking divisions and demonising his conservative opponents.