Clashes broke out after the game ended with hosts Arema FC of East Java’s Malang city losing to Persebaya Surabaya FC 3-2.
Thousands of Arema supporters, known as “Aremania”, reacted by throwing bottles and other objects at players and football officials.
The rioting spread outside the stadium where at least five police vehicles were overturned and set on fire amid the chaos.
Riot officers responded by firing tear gas, including towards the stadium’s stands, causing panic among the crowd. Tear gas is banned at football stadiums by Fifa.
Some people suffocated and others were trampled as hundreds ran to the exit in an effort to avoid the tear gas. In the chaos, 34 died at the stadium, including two officers, and some reports included children among the casualties.
East Java police chief Nico Afinta said in a news conference early on Sunday: “We have already done a preventive action before finally firing the tear gas as (fans) began to attack the police, acting anarchically and burning vehicles.”
More than 300 people were rushed to nearby hospitals but many died on the way and during treatment, Mr Afinta said.
He said the death toll is likely to increase because many of the approximately 180 injured who are receiving intensive treatment at various hospitals are deteriorating.
Indonesia’s football association, known as PSSI, has suspended the premier league Liga 1 indefinitely in light of the tragedy and banned Arema from hosting matches for the remainder of the season.
Television reports showed police and rescuers evacuating the injured and carrying the dead to ambulances.
Grieving relatives waited for information about their loved ones at Malang’s Saiful Anwar General Hospital. Others tried to identify the bodies laid out at a morgue.
Indonesian President Joko Widodo expressed his deep condolences for the dead in televised comments on Sunday.
“I deeply regret this tragedy and I hope this is the last soccer tragedy in this country. Don’t let another human tragedy like this happen in the future,” he said. “We must continue to maintain sportsmanship, humanity and a sense of brotherhood of the Indonesian nation.”
He ordered the youth and sports minister, the national police chief and the chairman of the PSSI to carry out a thorough assessment of the match and its security procedures.
He also ordered the PSSI to temporarily suspend Liga 1 until it can be evaluated and security procedures improved.
Youth and Sports Minister Zainudin Amali also expressed his regret that “this tragedy happened when we were preparing for soccer game activities, both national and international level”.
Indonesia is due to host the 2023 Fifa U-20 World Cup from May 20 to June 11, with 24 participating teams. As the host, the country automatically qualifies for the cup.
“Unfortunately, this incident has certainly injured our soccer image,” Mr Amali said.
Ferli Hidayat, local police chief of Malang, said there were some 42,000 spectators at Saturday’s game, all of whom were Aremanias because the organizer had banned Persebaya fans from entering the stadium in an effort to avoid brawls.
The restriction was imposed after clashes between supporters of the two rival teams in East Java’s Blitar stadium in February 2020 caused a total of 250 million rupiah (£14,614) in material losses. Brawls were reported outside the stadium during and after the semi-final of the East Java Governor’s Cup, which ended with Persebaya beating Arema 4-2.
Despite Indonesia’s lack of international accolades in the sport, hooliganism is rife in the football-obsessed country where fanaticism often ends in violence, as in the 2018 death of a Persija Jakarta supporter who was killed by a mob of hardcore fans of rival club Persib Bandung in 2018.
Saturday’s game is already among the world’s worst crowd disasters, including the 1996 World Cup qualifier between Guatemala and Costa Rica in Guatemala City where more than 80 died and some 100 others were injured.
In April 2001, more than 40 people were crushed to death during a football match at Ellis Park in Johannesburg, South Africa.