The chaos started just after the game between host Arema Football Club and Persebaya Surabaya. Arema lost to Persebaya, 3-2.
A police official told the Associated Press that all 42,000 spectators at the Kanjuruhan Stadium were supporters of Arema as Persebaya fans were prohibited from watching the match to avoid fights.
Arema fans charged into their home pitch to let out their frustration over the squad's first home defeat against Persebaya in 23 years.
A video shared on social media showed the fans on the field were immediately encountered by baton-wielding police with riot shields. (Related: Antifa throws Molotov cocktails at police during a riot in Portland)
Police then fired tear gas after much of the fans had cleared the field. Instead of controlling the crowd, the tear gas clouds caused a stampede to a narrow exit.
The New York Times reported that hundreds of people ran to an exit gate in an effort to evade the tear gas.
Some suffocated and others were crushed with 34 people killed almost immediately.
"There was a pile-up. The buildup process resulted in shortness of breath and lack of oxygen," said East Java Police Chief Nico Afinta. A video posted on Twitter showed fans climbing fences to avoid the tear gas.
"The stadium turned into a smoke-filled battleground when police fired tear gas. I felt hot and stinging in my eyes, I couldn't see clearly while my head was dizzy and everything went dark. I passed out," a fan told AP in an interview.
He woke in an emergency room to discover that his cousin died after suffering a head injury. "Tear gas was used because there was anarchy. They were about to attack the officers and had damaged the cars," said Afinta at a press conference about the incident.
Most observers are putting the blame on the police for the tragedy, citing FIFA game-management guidelines that ban the use of "crowd control gas."
Amnesty International has called for an inquiry while the soccer league has suspended play for at least a week.
Indonesian President Joko Widodo has already ordered an investigation. "I regret this tragedy and I hope this is the last tragedy of football in the country. We must continue to maintain sportsmanship, humanity and a sense of brotherhood of the Indonesian nation," Widodo said.
The New York Times reported that "violent, often deadly rivalries between major teams are common" in Indonesian soccer.
"Some teams even have fan clubs with so-called commanders, who lead armies of supporters to matches across Indonesia. Flares are often thrown on the field, and riot police are a regular presence at many matches. Since the 1990s, dozens of fans had been killed in soccer-related violence," the outlet noted.
Indonesia will host the FIFA under-20 World Cup from May to June next year. The nation is also bidding to host the 2023 Asian Cup, although Saturday's tragedy may have wiped out any chance of that occurring.
"Unfortunately, this incident has certainly injured our soccer image," said Youth and Sports Minister Zainudin Amali.
Meanwhile, Indonesian National Police spokesperson Dedy Prasetyo said Malang Police Chief Ferli Hidayat and nine elite officers were removed from their posts on Monday, Oct. 3. He added that 18 officers were under investigation for their role in the riot.
Prasetyo said police are investigating witnesses and reviewing video from 32 security cameras inside and outside the stadium.
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This video is from the Russia Truth channel on Brighteon.com.