With the end of the national mourning period for the Itaewon disaster, President Yoon Suk-yeol is now grappling with who to hold accountable amid continued revelations regarding the nation’s poor response and growing calls to sack related high-ranking officials.

At a national safety system inspection meeting held at the presidential office in Yongsan-gu, Seoul, on Monday morning, Yoon said, “We will strictly hold the responsible people accountable according to the (investigation’s) results.”

The president said he would ensure the truth is thoroughly investigated in connection with the disaster, vowing to fully disclose the process to the public.

Yoon also hinted at a major shakeup of the police, which is at the center of blame for its poor and late response to the accident. After the police's 112 report transcripts were released, criticisms grew over its inadequate reporting system.

“To protect the safety of the people, a major innovation is needed in the way police carry out their duties, which prepares for danger and prevents accidents,” Yoon said.

Lee Jae-myung, a vice spokesperson of the presidential office, said at a press briefing in the afternoon Yoon strongly criticized the police's response at the meeting, saying, "Why did (the police) just stare at (the accident) for four hours?" and “Does it make sense that the police have no authority in a chaotic situation?

Lee Im-jae, former chief of the Yongsan Police Station, and Ryu Mi-jin, former chief of personnel education and situation manager of the Seoul Metropolitan Police Agency on the day of the accident, were booked as suspects on Monday by the National Police Agency's special investigation division, which is investigating the Itaewon disaster. They were alleged not to have taken appropriate measures for the Oct. 29 disaster.

Other staff members were also booked for deleting an internal report that included concerns about crowd-related accidents during Halloween. Staff were found to have deleted the original version of the report immediately after the accident.

Opposition parties demanded the sacking of Police Commissioner General Yoon Hee-geun, Interior Minister Lee Sang-min and even Prime Minister Han Duck-soo, who made a quip at a media briefing with foreign journalists related to the disaster.

Minister Lee was notified about the disaster later than President Yoon -- not through the police or fire department, but through the ministry’s emergency notification sent out to all valid Korean phone numbers. He is also at the center of controversy for remarking the day after the incident that it would have occurred even with a larger police presence in Itaewon.

Commissioner General Yoon was also notified late about the incident. At 12:14 a.m. on Oct. 30 -- one hour and 59 minutes after the disaster -- he was notified through a call from a situation officer. In addition, it was revealed that the police failed to respond appropriately although several people called its emergency 112 hotline regarding crowding in Itaewon before the disaster occurred.

Lee said Monday he did not express his resignation to the presidential office and did not discuss the matter when asked by a lawmaker at a related committee meeting.

In the aftermath of the Itaewon disaster, President Yoon’s approval rating fell 1.5 percentage points from the previous week.

According to a Realmeter survey of 2,521 Korean adults nationwide for five days from Oct. 31 to Nov. 4 at the request of the Media Tribune, those who evaluated Yoon’s handling of state affairs positively was 34.2 percent.

"Although there was no significant drop in the social mourning atmosphere at the beginning of the week, the remarks of Interior Minister Lee Sang-min were re-examined, and the police's late and weak response continued to make the approval rating fall," said Realmeter senior expert Bae Chul-ho.

President Yoon belatedly apologized for the Itaewon disaster for the first time in public, six days after the disaster.

"As a president who is responsible for the lives and safety of the people, I feel sad and sorry," he said at a memorial rally for Itaewon victims at Jogyesa Temple on Friday.

A day later, he attended a church consolation service and bowed his head again, saying, "I'm sorry for not protecting the young people."