Fifteen minutes before kick-off, each banner is scrutinized at the security checkpoint at Ahmed bin Ali Stadium in the Qatari city of Al-Rayyan.
Two fans fold up a huge colorful tarp that is inspected elsewhere.
Next to them, four men in uniform surround an Iranian fan who has little understanding of the procedure so close to the start of the game against Wales.
He first rolls his eyes, then he rolls up the banner and when asked about the content, replies: "Greetings to my family in Tehran."
Christopher Ehrhardt
Correspondent for the Arab countries based in Beirut.
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Rainer Herman
Editor in Politics.
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After the game, women's rights activists report that they were detained for hours for wearing T-shirts emblazoned with the words "Women Life Freedom" and refusing to take them off.
Oddly enough, that wasn't a problem in the Brazil-Serbia game, says an activist.
When Iran plays Wales it's different.
Since September 16, protests have rocked the Islamic Republic.
The political crisis has long since spread to football, and so the game, a simple group game of the current World Cup, turned into a high-risk political game.
It is likely to be even more delicate when the Iran team meets the United States team this Tuesday, pitting two nations that are bitter opponents in the field of politics.
Anti-American hostility is part of the core ideology of the Iranian regime, which Washington has severely punished.
Taking to social media, the American Football Association removed the red emblem of the Islamic Republic from the wide white band of the Iranian flag.
Desire for a clear political signal
The Iranian Football Association countered at the weekend that Iran would lodge a complaint as soon as the team also defeated the United States.
Revolutionary leader Ayatollah Ali Khamenei, who is not known for his football enthusiasm, has once again made it clear that he does not want to give in to the demonstrators.
He berated them over the weekend as "a handful of strays and clueless mercenaries".
He wished the Iranian team "God's blessings" during his performance in front of militiamen from the Bassij, a notorious volunteer group.
The national team brings him joy, Khamenei said.
But in Iran, the often invoked unifying power of football doesn't seem to work.
When the national team wins, as they did against Wales on Friday, security forces stick flags in their guns.
Fireworks are set off or sweets are distributed.
But elsewhere, people are chanting the names of the players who are their heroes because they are showing solidarity with the protest movement.
The international players who are now on the pitch in Qatar are therefore under enormous pressure.
While the regime likes to bask in the glory of its successes, the opponents of the regime want the team in Qatar to send a clear political signal in the other direction.
Others have.
Former Bundesliga professional Ali Karimi, Iran's most famous professional footballer to date, now lives in Dubai and urged his 14 million followers on Instagram not to take a step back, otherwise "the bloodhounds of the Islamic Republic will celebrate their feasts on our corpses".
Before the game against Wales, the current internationals covertly sing along to the national anthem – unlike in the previous game against England, when they symbolically remained silent.
For some, that's not enough.
“You have to do a lot more than that. You should clearly show your colors.
You are protected by your notoriety,” says an Iranian fan in front of the stadium in Al-Rayyan.
His mother quickly jumps in front of a television camera to get rid of her dissident message.
For the two, however, the protest is comparatively harmless, they live in Europe.
Other fans living in Tehran are more merciful with the players.
“They must be afraid too.
Nobody is safe.
If we go out on the streets, we have to expect to be shot,” says one of them.