More than 150 people were killed in a stampede at a Halloween event in central Seoul, officials said Sunday, with South Korea's president vowing a full investigation into one of the country's worst-ever disasters.
The crowd surge and crush hit in the capital's popular Itaewon district, where estimates suggest as many as 100,000 people -- mostly in their teens and 20s -- went to celebrate Halloween Saturday night, clogging the area's narrow alleyways and winding streets.
President Yoon Suk-yeol declared a period of national mourning Sunday, telling the country in a televised address that "a tragedy and disaster occurred that should not have happened".
He said the government "will thoroughly investigate the cause of the incident and make fundamental improvements to ensure the same accident does not occur again in the future".
"My heart is heavy and it is difficult to contain my sorrow," he added, before he visited the scene of the disaster and spoke to emergency workers.
Seoul mayor Oh Se-hoon, who rushed back to South Korea from a work trip in Europe, said his office would set up a memorial altar at Seoul Plaza so the public could pay their respects to the victims, starting Monday morning.
"Most of the casualties are young people like our sons and daughters, which makes it even more sad," Oh said while visiting the site of the disaster.
Eyewitnesses described being trapped in a narrow, sloping alleyway, and scrambling to get out of the suffocating crowd as people piled on top of one another.
Seoul's interior ministry told AFP that 153 people had died, including 20 foreigners, in the stampede, which occurred around 10:00 pm local time (1300 GMT).
Most of the victims were young women in their 20s, it said, adding that 133 people were injured.
An official from Seoul's defence ministry said three military personnel were among the dead, including one soldier.
Seoul authorities said they had also received 2,642 reports of missing people.
- 'Unprecedentedly large' -
Officials said Sunday they had no clear idea of what caused the crush, while eyewitnesses described scenes of chaos after a vast crowd panicked in a narrow alleyway.
Local shopkeepers told AFP that the number of people at the annual celebration was "unprecedentedly large" this year -- the first event to be held without Covid-19 restrictions since the pandemic began.
"There were so many people just being pushed around and I got caught in the crowd and I couldn't get out at first too," 30-year-old Jeon Ga-eul told AFP.
As questions began to emerge over the lack of security at the event, interior minister Lee Sang-min told a briefing that the police force had been occupied on the other side of town.
"A considerable number had been deployed at Gwanghwamun where a large crowd was expected for a protest," he said.
Police had also not expected such a large crowd at the Halloween event, he said.
Paramedics at the scene, quickly overwhelmed by the number of victims, were asking passers-by to administer first aid.
In an interview with local broadcaster YTN, Lee Beom-suk, a doctor who administered first aid to the victims described scenes of tragedy and chaos.
"So many victims' faces were pale. I could not catch their pulse or breath and many of them had a bloody nose. When I tried CPR, I also pumped blood out of their mouths."
AFP photos showed scores of bodies on the pavement covered by bed sheets, and emergency workers dressed in orange vests loading even more bodies on stretchers into ambulances.
- 'Oh my god' -
Twitter user @janelles_story shared a video that she said showed Itaewon shortly before the stampede, in which hundreds of young people, many in elaborate Halloween costumes, are seen in a narrow street lined with bars and cafes.
The crowd appears in good spirits at first, but then a commotion begins and people start being pushed into one another. Screams and gasps are heard and a female voice cries out in English "Shit, shit!" followed by "Oh my god, oh my god!"
The interior ministry said the 20 foreigners killed included people from the United States, Uzbekistan, Austria, Norway, Vietnam, Kazakhstan, Iran, and Sri Lanka. Russia said three of its nationals had died.
China also confirmed that four of its nationals had died, with President Xi Jinping sending his country's "deep condolences for the victims" to Seoul.
Seoul's staunch ally, US President Joe Biden, said America "stands with" South Korea after the tragedy, while Japan's Prime Minister Fumio Kishida said he was "hugely shocked and deeply saddened" by the disaster.