A special inspection team under the Korean National Police Agency(KNPA) requested a formal police investigation into two senior superintendent-level officers for possible dereliction of duty during the deadly crowd crush over the weekend.

The team announced on Thursday that it has found deficiencies in the responses by Ryu Mi-jin, who was in charge of emergency call monitoring at the Seoul Metropolitan Police Agency(SMPA) on the day of the disaster, and Lee Im-jae, former head of the Yongsan Police Station overseeing the Itaewon area.

The inspectors said Ryu failed to promptly respond to about a dozen emergency calls received prior to the tragedy and delayed reports of the situation to the Seoul police chief and the situation room at the KNPA.

Lee is accused of arriving belatedly at the scene of the incident and also delaying briefings to higher-ups.

Earlier in the day, the KNPA removed Ryu from duty and placed her on disciplinary leave. It did the same for Lee on Wednesday. 

The ongoing probe will likely pick up speed after investigators raided situation rooms at the Seoul police agency and the Yongsan Police Station to obtain work logs.