The driver of a vehicle that plowed into pedestrians near Seoul City Hall last week, killing nine people, has admitted that he mistakenly entered the one-way street where the victims were standing.

At a press briefing on Tuesday, Seoul Namdaemun Police Station chief Ryu Jae-hyeok said the 68-year-old suspect, identified by his surname Cha, said it was his first time driving on the street and he was not aware that going straight or making a left turn onto the road was prohibited.

Asked when the suspect became aware that he was driving in the wrong direction, Ryu said the driver had likely realized it at the point of entry, but added that further investigations would be necessary to determine factors including whether the driver accelerated in an attempt to quickly get out.

The station chief said investigators are expected to probe whether the suspect, a city bus driver, had mistaken the gas pedal in his personal vehicle with that of the brake pedal in relation to the type of bus he normally operates.

While the suspect reportedly claimed the accident was caused by an auto defect, the police requested a forensic analysis to determine such a possibility, including sudden unintended acceleration.

The police first questioned the suspect, who is in hospital receiving treatment for a rib fracture, last Thursday. They plan to question him again on Wednesday.