SEOUL, South Korea (AP) — South Korean officials admitted responsibility and apologized on Tuesday for failures in preventing and responding to a Halloween crowd surge that killed more than 150 people and left citizens shocked and angry.

The government is facing growing public scrutiny over whether the crush Saturday night in Seoul’s Itaewon district, a popular nightlife neighborhood, could have been prevented and who should take responsibility for the country’s worst disaster in years.

National police chief Yoon Hee Keun said an initial investigation found there were many urgent calls from citizens notifying authorities about the potential danger of the crowd gathering in Itaewon. He said police officers who received the calls failed to handle them effectively.

“I feel a heavy responsibility (for the disaster) as the head of one of the related government offices,” Yoon said in a televised news conference. “Police will do their best to prevent a tragedy like this from happening again.”

Yoon said police have launched an intense internal probe into the officers’ handling of the emergency calls and other issues, such as the on-the-spot response to the crowd surge in Itaewon that night.

Separately, South Korea’s interior minister, emergency office chief, Seoul mayor and the head of a ward office that includes the Itaewon neighborhood all offered public apologies.

Seoul Mayor Oh Se-hoon apologized deeply and wept and briefly halted his news conference as he talked about the parent of a 20-year-old woman who was declared dead earlier in the day.

“When I tried to comfort a person with a daughter hospitalized at the National Medical Center yesterday, they said their daughter would survive and they believed so,” he said. “But I heard she passed away this morning. I am sorry that my apology has come late.”

The disaster — which left at least 156 people dead and 151 others injured — was concentrated in a narrow downhill alley in Itaewon. Witnesses described people falling on one another, suffering severe breathing difficulties and falling unconscious. They said rescuers and ambulances failed to reach the crammed alleys in time because the entire Itaewon area was packed with slow-moving vehicles and partygoers clad in Halloween costumes.

Most of the dead were in their 20s and 30s, and about two-thirds were women.

During a Cabinet council meeting Tuesday, President Yoon Suk Yeol acknowledged that South Korea lacks research on crowd management. He called for the use of drones and other high-tech resources to develop an effective crowd control capability, and said the government will soon meet with experts to review national safety rules.

The crowd surge is South Korea’s deadliest disaster since a 2014 ferry sinking that killed 304 people and exposed lax safety rules and regulatory failures. Saturday’s surge has raised public questions about what South Korea has done since then to prevent human-made disasters.

“My heart is aching a lot as all the victims were like my grandchildren,” 74-year-old Chung Kil-soon said after paying respects at a mourning station Tuesday. “People say our country is an advanced country, but I don’t think we are truly advanced.”

After the Itaewon disaster, police launched a 475-member task force to find its cause.

Senior police officer Nam Gu-Jun told reporters Monday that officers have obtained videos taken by about 50 security cameras in the area and were analyzing video clips posted on social media. Nam said police had also interviewed more than 40 witnesses and survivors so far.

Police said they had sent 137 officers to maintain order during the Halloween festivities on Saturday, much more than the 34-90 officers mobilized in 2017, 2018 and 2019 before the pandemic. But some observers questioned whether the 137 officers were enough to handle the estimated 100,00 people gathered Saturday in Itaewon.

Adding more questions about the role of police was the fact that they sent 7,000 officers to another part of Seoul earlier Saturday to monitor dueling protests involving tens of thousands of people. Police also acknowledged that the 137 officers dispatched to Itaewon were primarily assigned to monitor crime, with a particular focus on narcotics use, not crowd control.

The death toll could rise as officials said that 29 of the injured were in serious condition. The dead included 26 foreign nationals from Iran, China, Russia, the United States, Japan and elsewhere.

President Yoon asked officials to provide the same government support to the bereaved families of the foreign victims as for the South Korean dead and injured people. He also thanked many world leaders for sending condolence messages.

The Itaewon area, known for its expat-friendly, cosmopolitan atmosphere, is the country’s hottest spot for Halloween events and parties, with young South Koreans taking part in costume competitions at bars, clubs and restaurants. Saturday’s gathering was the biggest Halloween celebration in the area since the pandemic.

Halloween festivities in Itaewon have no official organizers. South Korean police said Monday they don’t have any specific procedures for handling incidents such as crowd surges during an event that has no organizers.