Prosecutors filed for pretrial detention of a suspect accused of attacking main opposition Democratic Party(DP) leader Lee Jae-myung with a weapon during his visit to the southeastern port city of Busan on Tuesday.

An official at the Busan District Prosecutors' Office said the warrant request was made on Wednesday, in consideration of the gravity of the alleged attempted murder, the flight risk of the suspect and the possible destruction of evidence.

The prosecution said it will closely cooperate with the police to thoroughly investigate the truth behind the attack, such as the suspect's motive.

A court hearing for the pretrial detention of the 67-year-old suspect, identified by his surname Kim, is set to begin at 2 p.m. Thursday.

Kim stabbed the left side of the DP chief's neck after approaching him under the pretense of being a supporter while Lee inspected the site of delayed construction for a new airport on Gadeok Island. Kim was apprehended at the scene of the attack.

On Wednesday, Busan police raided Kim's residence, office and vehicle in the South Chungcheong provincial city of Asan to obtain his personal computer, laptop, and other items.