SEOUL - At least 153 people were killed in a crush when a huge crowd celebrating Halloween surged into an alley in a nightlife area of the South Korean capital Seoul on Saturday night, emergency officials said.

Most of those who died were said to be teenagers and people in their 20s. Authorities said 22 foreigners were killed, including those from Iran, Uzbekistan, China and Norway.

At least a further 133 people were injured in the melee in Seoul’s Itaewon district, Mr Choi Sung-beom, head of the Yongsan Fire Station, said in a briefing at the scene.

Nineteen of the injured were in serious condition and receiving emergency treatment, the officials said, adding the death toll could rise.

It was the first Halloween event in Seoul in three years after the country lifted Covid-19 restrictions and social distancing. Many of the partygoers were wearing masks and Halloween costumes.

Some witnesses described the crowd becoming increasingly unruly and agitated as the evening deepened. The incident took place at about 10.20pm (9.20pm Singapore time).

“A number of people fell during a Halloween festival, and we have a large number of casualties,” Mr Choi said. Many of those killed were near a nightclub.

Many of the victims were women in their 20s, Mr Choi said.

Witnesses described chaotic scenes moments before the crush, with the police on hand in anticipation of the Halloween event at times having trouble maintaining control of the crowds.

Mr Moon Ju-young, 21, said there were clear signs of trouble in the alleys before the incident.

“It was at least more than 10 times crowded than usual,” he told Reuters.

Social media footage showed hundreds of people packed in the narrow, sloped alley crushed and immobile as emergency officials and police tried to pull them free.

Mr Choi, the Yongsan district fire chief, said all the deaths were likely from the crush in the single narrow alley.

Other footage showed chaotic scenes of fire officials and citizens treating dozens of people who appeared to be unconscious.

A witness quoted by JoongAng Daily said he tried to leave Itaewon’s main pedestrian entertainment street via a small side street next to the Hamilton Hotel.

He escaped before the crush turned deadly but said that other people were already panicking, with some in tears.

“It was people fighting to leave and people fighting to get in,” he said.

Fire officials and witnesses said people continued to pour into the narrow alley that was already packed wall-to-wall, when those at the top of the sloped street fell, sending others below them toppling over others.

An unnamed woman who said she was the mother of a survivor said her daughter and others were trapped for more than an hour before being pulled from the crush of people in the alley.

A Reuters witness said a make-shift morgue was set up in a building adjacent to the scene. About four dozen bodies were carried out later on wheeled stretchers and moved to a government facility to identify the victims, according to the witness.

The Itaewon district is popular with young South Koreans and expatriates alike, its dozens of bars and restaurants packed on Saturday for Halloween after businesses had suffered a sharp decline over three years of the pandemic.

The Korea Herald reported that around 100,000 people had flocked to the nightlife district to celebrate. Revellers were not required to wear face masks or observe social distancing measures. 

“You would see big crowds at Christmas and fireworks ... but this was several ten-folds bigger than any of that,” Mr Park Jung-hoon, 21, told Reuters from the scene.

A report by local broadcaster YTN said an unidentified celebrity visited a bar in the area, which drew a massive crowd. 

Foreigners were among those transferred to nearby hospitals.

Casualties were being taken to Soonchunhyang University Hospital, the National Medical Centre, Ewha Womans University, Mokdong Hospital and Kangbuk Samsung Hospital, said JoongAng Daily.

British Prime Minister Rishi Sunak tweeted: “All our thoughts are with those currently responding and all South Koreans at this very distressing time.”

US President Joe Biden and his wife sent their condolences and wrote: “We grieve with the people of the Republic of Korea and send our best wishes for a quick recovery to all those who were injured.” 

US Secretary of State Antony Blinken tweeted: “We send our thoughts and deepest condolences to the family and friends of the deceased and injured, as well as to the people of (South Korea) as they mourn this horrific tragedy.”

With the easing of the Covid-19 pandemic, curfews on bars and restaurants and a limit of 10 people for private gatherings were lifted in April. An outdoor mask mandate was dropped in May.

President Yoon Suk-yeol presided over an emergency meeting with senior aides and ordered a task force be set up to secure resources to treat the injured and to launch a thorough investigation into the cause of the disaster.

City officials, meanwhile, told Yonhap that Seoul Mayor Oh Se-hoon had decided to return from a trip to Europe in the wake of the incident.

The news agency said a total of 848 personnel, including 346 firefighters, were mobilised for the area.

Authorities said they were investigating the exact cause of the incident.