A suspect behind the armed attack on main opposition Democratic Party(DP) leader Lee Jae-myung during a visit to Busan Tuesday morning is reportedly refusing to talk to police.

The man, presumed to be in his 60s or 70s, lacerated the left side of Lee's neck after approaching him while pretending to be a supporter during the DP chief's inspection of the site of delayed construction for a new airport on Gadeok Island.

According to the Busan Gangseo Police Station, the suspect, who kept mum as he was taken into custody immediately after the attack, is exercising the right to remain silent.

The police are expected to give a press briefing on their preliminary investigation Tuesday afternoon.

Lee was transported by helicopter to a hospital some 20 minutes away after the attack, having received medical treatment on-site for a wound around one centimeter long, with the police saying that he was not gravely injured.