Rescue team members wait with stretchers to remove bodies from the scene where dozens of people were injured in a stampede during a Halloween festival in Seoul, South Korea, October 29, 2022. (REUTERS/Kim Hong-ji)

A further 65 people were injured in the melee in Seoul's Itaewon district, Choi Sung-beom, head of the Yongsan Fire Station, said in a briefing at the scene.

It was the first Halloween event in Seoul in three years after the country lifted COVID 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 10:20 p.m. (1320 GMT).

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

Many of the victims were women in their twenties, Choi said.

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

Police officers walk at the scene where many people died and were injured in a stampede during a Halloween festival in Seoul, South Korea, October 30, 2022. (REUTERS/Kim Hong-ji)

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 to free.

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

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 people below them toppling over others.

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.