SEOUL, Oct 30 — Party-goers in costumes fleeing in panic, desperate attempts at first aid on the sidewalks, scores of bodies lined up under makeshift shrouds: in Seoul's lively Itaewon district, a Halloween festival turned to tragedy Saturday.

More than 150 people — mostly in their teens and 20s -— were killed in a crowd surge and stampede, the cause of which is still unclear, in this popular, cosmopolitan district of the South Korean capital, located close to a former US military base and renowned for its bars and clubs.

Tens of thousands of people, many wearing elaborate Halloween costumes, had descended upon the district Saturday night, for the first major Halloween celebration since South Korea lifted most Covid-19 restrictions.

"My friend said: something terrible is happening outside," said Jeon Ga-eul, 30, who was having a drink at a bar at the moment the stampede hit.

"I said: what are you talking about? And then I went outside to see and there were people doing CPR in the street."

The district, which was immortalised by the popular 2020 K-Drama hit Itaewon Class, is a warren of steeply sloping, twisted alleyways on either side of the main road.

The crowd was exceptionally dense on Saturday night, eyewitnesses told AFP, with Jeon saying that even ahead of the disaster, he had felt unsafe.

"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," he said.

The fire department said the dead included 97 women and 54 men, and eye-witnesses told the Yonhap News Agency that smaller people had struggled more in the crowds.

"A short person like me could not even breathe," a female eye-witness said, adding that she had survived as she was at the edge of the alleyway while "people in the middle suffered the most."

Bystanders help

The stampede took place in a narrow, sloping alley near the Hamilton Hotel in Itaewon.

One eye-witness described on Twitter the panic that started when people "kept pushing down" into the already crowded alleyway.

This resulted in "other people screaming and falling down like dominoes," the Twitter user with the handle "jkaesthet1c" wrote.

"I thought I would be crushed to death too as people kept pushing without realising there were people falling down at the start of the stampede," they added.

Some survivors claimed that nearby stores and establishments on the alleyway had blocked people from coming in to escape the crush.

"It looks like the casualties were more severe as people attempted to escape to nearby stores but were kicked out back to the street because business hours were over," one survivor told Yonhap.

Faced with a huge number of victims, the first emergency responders were asking passers-by to administer first aid and perform CPR on victims in the streets, just next to the chaos.

The bodies of people who had been crushed or trampled to death lay in rows, covered with blankets or makeshift shrouds.

Dazed passers-by sat on the sidewalk, checking their phones. Others comforted themselves, hugging each other.

Early Sunday, police investigators had sealed off and were examining the debris-strewn alleyways, where bits of discarded Halloween costumes and garbage were still strewn over the paving stones.

South Korea's President Yoon Suk-yeol, who declared a period of national morning in a televised address, visited the site of the accident and spoke to police and other officials.

"It's always crowded, but nothing like this has ever happened before," Ju Young Possamai, 24, a bartender in the Itaewon district told AFP.

"I've been to a lot of Halloween parties in Korea," he said, adding: "I never thought that something like this could happen in Korea, especially in Itaewon." — AFP