A person offers flowers at a temporary mourning space near the scene of a tragic Halloween stampede in Seoul's Itaewon district, Oct. 31. Yonhap

The death toll from the Halloween crowd crush in Seoul has risen to 154, including 26 foreigners, officials said Monday, as the country mourned the deadliest tragedy in years and tried to cope with the aftermath.

The death toll could rise further, as 33 others remain in serious condition, according to officials at the Central Disaster and Safety Countermeasures Headquarters. A total of 116 others sustained minor injuries, they said.

All but one of the fatalities have been identified, officials said.

The 26 foreign victims include five from Iran, four each from China and Russia, two from the United States, two from Japan, and one each from France, Australia, Norway, Austria, Vietnam, Thailand, Kazakhstan, Uzbekistan, and Sri Lanka, officials said.

Among those killed were one middle schooler and five high school students, all from Seoul, the education ministry said. Five other middle or high school students have been injured, and two of them were being treated at hospitals, it said.

The tragedy happened Saturday night when a massive crowd of Halloween partygoers packed a narrow 3.2-meter-wide alley in Seoul's entertainment district of Itaewon. Some of them began to fall over, causing others to fall down like "dominoes" and pile up on one another.

It marked the deadliest crowd crush in Korea's history and the worst disaster the country has seen since 2014, when the ferry Sewol sank in waters off the south coast and killed 304 people, mostly high school students.

The site of the accident is a downhill 40-meter back alley that links a busy restaurant district with a main street, where about six adults can barely pass at the same time.

Flowers are displayed to pay tribute for victims near the scene of a deadly accident in Seoul, Oct. 30. AP

Tens of thousands of people were visiting the area for Halloween festivities after the government lifted the outdoor mask-wearing mandate against the COVID-19 pandemic earlier this year.

Most of the fatal victims were in their 20s, and the majority of those killed were women at 98, due largely to what experts say is their relatively smaller frame and fewer muscles to resist crushing pressure.

A government probe in currently under way to determine the exact cause of the accident.

On Sunday, President Yoon Suk-yeol announced a weeklong national mourning period starting Sunday and ordered the lowering of flags.

The government plans to set up a mourning altar in central Seoul to allow people to pay tribute to the victims.

People began to lay flower bouquets, white mourning flowers and candy near the accident scene in Itaewon on Sunday, and many visited the site to mourn the deaths of young victims.

"I came out to pray for the victims and their families," a 29-year-old citizen, surnamed Yoon, told Yonhap News Agency after paying tribute in the neighborhood late Sunday. "I hope that people can find hope in the midst of despair." (Yonhap)