South Korea’s police chief said on Tuesday officers had received several urgent danger reports in front of a deadly crowd at a Halloween event, but their handling of them was “inadequate”.

At least 156 people, mostly young, were killed and dozens more injured in a deadly crowd late Saturday at the first post-pandemic Halloween party in Seoul’s popular nightlife district of Itaewon.

An estimated 100,000 people had poured into the area, but as it was not an “official” event with a specific organizer, neither police nor local authorities actively dealt with the crowds.

“Just before the accident happened, the police received several reports indicating the seriousness of the accident site,” said national police chief Yoon Hee-keun.

The police knew “that a large crowd had already gathered before the accident, urgently warning of the danger,” he said, admitting that the handling of this information was “inadequate”.

South Korea tends to be strong at crowd control, with protest rallies often being so heavily policed ??that officials can outnumber the attendees.

But in the case of the Itaewon Halloween celebrations, there was no designated organizer and people flocked to the area to attend events hosted by individual bars, clubs and restaurants.

Police said they dispatched 137 officers to Itaewon for Halloween – but 6,500 officers were present at a citywide protest attended by only about 25,000 people, local reports said.

South Korean President Yoon Suk-yeol said Tuesday the country urgently needs to improve its system for handling large crowds in the wake of the disaster.

“People’s safety is important, regardless of whether there is an organizer or not,” he said at a cabinet meeting.

He called on the country to develop “state-of-the-art digital skills” to improve crowd management – but critics claim such tools already exist and have not been used in Itaewon.

Seoul City Hall has a real-time crowd monitoring system that uses cellphone data to predict crowd size, but it was not deployed on Saturday night, local media reported.

Itaewon county authorities also did not deploy security patrols, with officials saying the Halloween event was viewed as a “phenomenon” rather than a “festival,” which would have required an official crowd control plan.

During the night, tens of thousands of people crowded a narrow alley, and eyewitnesses described how confused partygoers with no police or crowd control in sight pushed and shoved, crushing those trapped in the alley.

Analysts say this was easily avoidable, even with only a small number of police officers.

“Good safe crowd management isn’t about ratio, it’s about crowd strategy – for safe crowd capacity, flow, density,” said G. Keith Still, Professor of Crowd Science at the University of Suffolk.

South Korean expert Lee Young-ju said that if local police had known they would be understaffed, they could have sought help from local authorities or even from residents or shopkeepers.

“It’s not just the numbers,” Lee, a professor in the Department of Fire and Disaster at the University of Seoul, told AFP.

“The question is how they coped with the limited number (of the police) and what measures they took to compensate.”