How hooligans exposed the ugly rift in Croatian football
If the Maksimir Stadium were a choir, the Bad Blue Boys would be the conductors.
Perched high up behind one goal, their strident cry of "Dinamo!" receives a lusty response of "Zagreb!" from the other three sides of the ground.
They are among the best-known fan groups in Europe and are preparing for another a taste of the Champions League group stage.
It is all a far cry from the disgraceful scenes of violence involving Croatian fans at Euro 2016, when flares were thrown on to the pitch and hooligans appeared to be sabotaging their own team.
And yet in Zagreb it is easy to see that there is something wrong with the Bad Blue Boys, and with Croatian football in general.
Leading the chants behind the goal are just a few dozen supporters, and the near 40,000-capacity Maksimir is barely a third full.
- Croatia football boss criticises 'sports terrorists'
- Croatia football officials arrested
- Croatian federation apologies for swastika on pitch
- Dinamo to face Juventus in Champions League
"Zagreb has grown apart from its club," says Croatian football writer Juraj Vrdoljek, "The Bad Blue Boys have been in a long-term war with the board of the club itself."
Strange, perhaps, considering the team's uninterrupted domestic dominance since 2005; the success of ex-Dinamo players Luka Modric, Mario Mandzukic and, most recently, Marko Pjaca; and Dinamo's own advances in the Champions League, beating Arsenal last season.
Allegations of corruption
But beneath the glitter there is a grubby tale of corruption charges, political impotence and tasteless acts of hooliganism.
The leading character is Zdravko Mamic, formerly chief executive of Dinamo and, until last month, a vice-president of the Croatian Football Federation (HNS).
In April, Croatia's anti-corruption office charged him and three other people with embezzling around €15m (£13m; $17m) from the club - as well as making undeclared profits from high-profile transfers.
Mr Mamic and the others have denied the charges.
But this begins to explain the discontent seeping through Croatian football.
For years, fans have alleged that Mr Mamic and his allies were using a club that belongs to the public as a source of private profit. And they were unhappy about his role at the Football Federation.
Supporters of other clubs - notably Dinamo's greatest domestic rival, Hajduk Split - have been involved in campaigns for greater transparency as well.
And they felt they had scored a significant victory when Croatia's parliament adopted a new Law on Sports in 2015.
"Dinamo supporters have been engaged throughout the years in action against people in charge of the club as well as the Football Federation. They consider them to be part of a corrupt system," says Juraj Vrdoljek.
The legislation gave all sports clubs and associations six months to revise their financial and leadership structures to make them more transparent.
Fans hoped this would result in the end of the old power structure at the Football Federation, which not only prominently featured Zdravko Mamic but was dominated by leading members of the Croatian nationalist party, the HDZ.
However, the federation argued that it should not have to comply with the new law, and simply carried on as before.
When the HDZ returned to power in January, its governing coalition did nothing to enforce the changes.
Fast-forward to Euro 2016 and the pyrotechnics and punch-ups at the European Championship in France.
"That wasn't a simple hooligan act," insists Juraj Vrdoljek.
"It was the final act in a long-lasting war between the fans and the Croatian Football Federation.
"The people in the federation tend to present it as a hooligan problem, to change the focus from the problem in football itself which caused the violence to escalate. The bigger problem is the structure of the federation in general and the way it's been run."
The outrage among fans had been clear for some time.
The federation was fined and the Croatian team had a point deducted when a swastika was burned on to the pitch at Split before a Euro 2016 qualifying tie.
'Power-grab' by fans
The Football Federation rejects the view that all the incidents have been part of an idealistic crusade against alleged corruption. Rather, says security commissioner Miroslav Markovic, the fan groups are attempting a power-grab of their own.
"They think they can lead football clubs - they want to be the owners," he says. "Every faction of the supporters' groups wants something - money, power - and when they can't participate, they start to make trouble to punish the clubs and force them into a deal."
In the wake of the crowd trouble at Euro 2016, the federation appealed to the government for help.
And wary of the potential damage to Croatia's international image, Foreign Minister Miro Kovac has promised his backing. As long as the HDZ is still in power after elections in September.
"It is not acceptable that so-called fans from Croatia travel to foreign countries, and then have wars against the Football Federation and create a very bad image of our country and our people," says the minister.
"We need a very tough stance from the government. We have to fight against hooliganism in Croatia and educate our youth that the misuse of sport for personal political purposes is not acceptable."
From the outside it seems bizarre that Croatia's successful, attractive national team has become such a focus of discontent as well as an international embarrassment.
But the relationship between fans and the authorities is as rancorous as the fiercest rivalries in football. And without radical change, the ugly scenes of Euro 2016 may not be over.