STORY: Indonesian police wrongly used tear gas inside a soccer stadium to disperse rioting fans, according to an internal oversight official with the National Police Commission.
Police, experts and spectators - along with video footage - suggest Saturday's tragedy, which killed at least 125 people, was caused by a number of factors.
They include tear gas, an overcrowded stadium, angry fans of the losing home team, and locked exits.
The official said there were no orders to use tear gas on the crowd, and that it was unclear why some exits had been locked.
Arema FC supporter Ahmad Nizar Habibi spoke to Reuters:
"Why are we sacrificing supporters? Forgive me, but if it were just hits or being chased down by batons or being kicked, we can run away, we can find cover. But with this gas, what were we supposed to do? In a stadium that's enclosed, no open doors, tear gas came straight to fellow supporters. Was that supposed to be done?"
Spectators said several of the exit gates were locked, causing bottlenecks as fans tried to flee.
Yusuf Kurniawan is a football commentator in Indonesia.
"The most fatal mistake was deploying tear gas and causing panic because it floated up into the stands affecting even those who didn't even go down (to the field). People panicked and they were suffocated as they struggled to find the exits which were locked, and that's where chaos happened and people died."
Football's world governing body FIFA bans the use of "crowd control gas" and weapons at matches.
Police have said the decision to deploy it is one of the issues being investigated.
With the country in mourning and seeking answers, the spotlight may be on the police but experts say the true picture is more complicated.
Football hooliganism and violence is not new in Indonesia.
To pre-empt risks, the police had banned fans from the rival Persebaya Surabaya side from attending.
And asked for the match to be held during the day, when policing is easier, according to private football watchdog Save our Soccer (SOS).
But SOS also said organizers printed 42,000 tickets for a stadium designed to hold only 38,000.
"We cannot only blame the police. These are collective mistakes," SOS said.
A spokesperson from Arema FC was not immediately available for comment.
Indonesia's soccer federation has banned two club officials for life over the chaos.
Spokespeople for the national and East Java police declined to answer questions on the security measures, but on Monday, 10 officers were suspended pending an investigation.