All team members remained silent in a move being seen as a signal of support for anti-government protesters in Iran, hundreds of whom have reportedly been killed.
Iran's World Cup football team stayed silent as the national anthem was played before their opening World Cup match, declining to sing before the kick-off against England.
During the week, their captain Alireza Jahanbakhsh had explained that the players would decide "collectively" whether or not to sing the anthem as a sign of support for the victims of the harshly repressed protests in their country.
The players kept their faces totally impassive, while on the bench a member of the delegation sang. Iranian state television did not show the players lined up for the anthem before the match got under way in Qatar, just across the Gulf from their homeland.
Many fans back home had accused the squad of siding with a violent state crackdown on persistent popular unrest. Dozens of Iranian public figures, athletes and artists have displayed solidarity with the protesters -- but no Iranian player from the national squad had voiced support, until Monday's match.
A banner in the Iranian-occupied stands read "Woman Life Freedom" in English and was quickly removed. Some Iranian fans who went to Qatar for the World Cup have made no secret of their solidarity with the unrest.
Protests demanding the fall of the ruling Shi'ite Muslim theocracy have gripped Iran since the death two months ago of young woman Mahsa Amini after her arrest for flouting the strict Islamic dress code.
The activist HRANA news agency said 410 protesters including 58 minors, and 54 members of the security forces, had been killed in the unrest as of Saturday, with at least 17,251 people arrested.
The World Cup in Qatar ran into more controversy earlier on Monday when FIFA threatened to issue yellow cards to any player wearing 'OneLove' armbands, introduced to support diversity and inclusion.
The captains of England, Wales, Belgium, the Netherlands, Switzerland, Germany and Denmark will not wear 'OneLove' armbands at the World Cup under pressure from FIFA, their associations said in a joint statement on Monday.
"As national federations, we can't put our players in a position where they could face sporting sanctions including bookings, so we have asked the captains not to attempt to wear the armbands in FIFA World Cup games," the statement said, hours before England's match against Iran was due to kick off.
The move attracted swift and scathing criticism from groups representing the LGBT+ (lesbian, gay, bisexual, transgender) community.
Human rights campaigner Peter Tatchell, speaking on Sky News, condemned FIFA's move as a "deliberate attempt to prevent support" for LGBT+ communities, describing FIFA as "the bully in the room and the culprit".