Iran’s players sung their national anthem before the match against Wales amid jeers and tears from fans inside the Ahmad Bin Ali Stadium.
The players had very noticeably stayed silent ahead of Monday’s defeat against England, but they did tentatively sing on Friday following reports they could face reprisals if they again kept quiet.
Their silence on Monday was seen as a symbolic show of support for the protest movement in Iran following the death of 22-year-old Mahsa Amini in police custody in September.
Mehdi Chamran, the chairman of Tehran city council, had said on Tuesday that “we will never allow anyone to insult our anthem and flag” and that their civilisation had a history spanning thousands of years.
The players did sing when the anthem played before their match against Wales but this was accompanied by loud boos and jeers. Some Iran fans inside the stadium were in tears.
Others had arrived holding flags in protest at Amini’s killing and were seen being spoken to by security for the World Cup organisers. One steward could be seen apparently remonstrating with a man who was holding a banner that said "woman, life, freedom" on it.
The Associated Press also reported angry scenes outside the stadium. They said groups of men chanted "The Islamic Republic of Iran"at women giving interviews about the protests to media outside the stadium. They also reported "shouting matches" outside a security checkpoint between fans screaming "Women, Life, Freedom" and others "The Islamic Republic".
Iran manager Carlos Queiroz had confronted a BBC journalist on Thursday after another press conference was dominated by questions over political issues in Iran. Queiroz wanted to know why other managers, including England’s Gareth Southgate, do not face questions on political situations in their countries.
"I ask the pleasure to talk with you," said Queiroz. "I am asking one thing to you now, the press conference is finished. Do you think it is fair also to ask other questions to other coaches?
"That is the only question I make. Why don’t you ask the other coaches? Why you don’t ask Southgate ‘what do you think about England and the United States that left Afghanistan and all the women alone?’ Why don’t you ask that?"
There were also reports of a woman holding a shirt with the name 'Mahsa Amini' on it before having the shirt removed by security.