Rescuers work at the site of a stampede accident in Itaewon, a district of Seoul, South Korea, on Saturday. At least 146 people were killed and 150 others injured in a stampede accident that occurred Saturday night at Itaewon, a district of the South Korean capital Seoul, during Halloween gatherings, local authorities said early Sunday morning. XINHUA/VNA Photo

SEOUL — At least 149 people have been killed and 76 others injured in a deadly stampede in Seoul's Itaewon district as huge crowds of partygoers, many in their late teens and 20s, converged in the entertainment district for late-night Halloween celebrations.

The deadliest stampede in South Korea's history happened Saturday night in a narrow downhill alley near Hamilton Hotel in the famous nightlife district after tens of thousands of people visited the area for Halloween.

A total of 149 people have been killed and 76 others injured, 19 of them seriously, fire authorities said, adding the death toll could rise further.

Two of the dead and 15 of the injured were foreigners.

Choi Seong-beom, head of the fire department in Yongsan, which includes Itaewon, told reporters "many casualties were incurred as a crowd of people fell over during Halloween parties."

It was the first Halloween event in Seoul in three years after the country lifted many COVID-19 restrictions. Most of the people on the streets were wearing Halloween costumes.

Victims in their late teens and 20s accounted for the age group most affected by the accident, the authorities also said. It is not yet known whether the victims included minors.

Video footage showed rescue workers and ordinary people conducting CPR on victims on the streets.

Fire authorities initially received dozens of reports from people in the Itaewon area about patients with breathing difficulties. The first report was made around 10:15pm.

Rescuers sent to the scene had administered CPR on dozens of victims on a nearby road.

"As people in the front fell over, those in the back were crushed," a witness in his 20s told Yonhap News Agency.

Rumors at the scene were that a crowd of people had flocked to a place to see a celebrity or candies laced with drugs had been distributed at clubs, but the exact cause of the accident is yet to be known.

Shortly after the stampede, President Yoon Suk-yeol presided over two successive emergency meetings, ordering officials to swiftly administer first aid and treat the injured, the presidential office said.

Yoon also ordered officials to deploy emergency medical officials to Itaewon and secure emergency beds.

After presiding over an emergency meeting on the stampede, Yoon instructed officials to thoroughly investigate the cause of the accident.

Separately, Prime Minister Han Duck-soo instructed officials to make utmost efforts to minimize damages.

Seoul Mayor Oh Se-hoon, who is on a visit to Europe, decided to return home in the wake of the accident, city officials said.

A total of 848 personnel, including 346 firefighters, were mobilised for the area.

As of early Sunday, some 270 missing reports were made in connection with the accident, the Seoul city government said.

Police said they are making utmost efforts in confirming the identity of the victims and then making contacts with their family members.

Police plan to launch an investigation soon into whether bars and clubs in the area were in compliance with safety regulations.

US President Joe Biden expressed his "deepest condolences".

"Jill and I send our deepest condolences to the families who lost loved ones in Seoul. 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," Biden said in a statement, referring to first lady Jill Biden.

"The Alliance between our two countries has never been more vibrant or more vital – and the ties between our people are stronger than ever. The United States stands with the Republic of Korea during this tragic time," he said. YONHAP