At least 151 people have been killed and 82 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.

As of 9 a.m. Sunday, a total of 151 people, including 19 foreigners, have been killed and 82 others injured, 19 of them seriously, according to Choi Seong-beom, head of the fire department in Yongsan, which includes Itaewon.

Of the deceased, 97 are female and 54 are male, Choi said.

The foreigners killed include those from Iran, Uzbekistan, China and Norway, he said.

The stampede marked the worst tragedy in South Korea since the 2014 sinking of the ferry Sewol that killed 304 people, mostly high school students.

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 10:15 p.m.

Witnesses and survivors say a massive group of people surged into the downhill alley with a width of about 4 meters and were instantly pushed down by others.

"People kept pushing down into a downhill club alley, resulting in other people screaming and falling down like dominos," an unidentified witness wrote on Twitter. "I thought I would be crushed to death too as people kept pushing without realizing there were people falling down at the start of the stampede."

President Yoon Suk-yeol addressed the nation live from the presidential office, saying Saturday's "tragedy and disaster should never have happened."

The president also announced a period of national mourning over the stampede.

Before addressing the nation, Yoon also 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.

As of early Sunday, 355 missing person reports had been 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.

(Source: Yonhap)