A police line blocks entry to an alley in Itaewon district in Seoul where a stampede during Halloween parties killed at least 151 people and injured 82 others, Oct. 30. Yonhap

Witnesses and survivors on Sunday said an overnight stampede that killed at least 151 people occurred after a massive group of people celebrating Halloween surged into a narrow downhill alley and were instantly pushed down by others.

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

A total of 151 people, including 19 foreigners, have been killed and 82 others injured, fire authorities said, adding the death toll could rise further.

"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."

A woman her 20s said the accident occurred after a massive crowd of people were pushed back and forth for some time, which then led her friend to be pinned down under the crowd.

Another female survivor in her 20s, surnamed Park, said the stampede erupted as people flocked into the small street in a short period of time.

"A short person like me could not even breathe," Park said. "(I) could survive as I was located on the sideline of the alley. It looks like people in the middle suffered the most."

Another survivor, who asked not to be named, said the rescue operation got behind as the streets were flooded with people in Halloween costumes, making it difficult for emergency workers to arrive at the alley.

Other survivors, meanwhile, blamed the owners of bars and clubs nearby, who allegedly blocked people from escaping from the overcrowded alley.

"It looks like the casualties were more severe as people attempted to escape to nearby stores but were kicked out back to the street because business hours were over," said the survivor who asked not to be named. (Yonhap)