Reports from Iran indicate an "intense clash" between security forces and angry fans attending a football match in Tehran on Friday.
Reports from Tehran also say thousands of football fans at Tehran's Azadi Stadium chanted anti-government slogans in the course of the clash which appeared to be not politically motivated in the first place.
A video received by Radio Farda and uploaded on Friday, shows the crowd chanting "Death to the dictator."
The video is said to have been shot during a match between Tehran's leading team Esteghlal and Tabriz's champion Tractor, Friday evening. Tractor's fans are mainly ethnic Azeris who travel long distances to accompany their local champions.
The clashes seem not to be the result of chanting anti-government slogans, as three different events were happening at the same time.
While Tractor fans were unhappy with their treatment and the match, clashing with the police, almost everyone in the stadium was chanting opposition slogans. At the same time, as the game progressed, rival fans also clashed.
In other videos, thousands of spectators chant slogans such as "This is the Zionist regime," in some kind of answer to the Islamic Republic's anti-Israeli rhetoric which blames every violent or bad event on Israel, which it calls "the Zionist regime." The slogan means, it is the Islamic regime that is the culprit in all mischiefs.
Another slogan which rhymes nicely in Persian, is "Guns, tanks, fireworks, the clerics must get lost!" is self-explanatory, although the rhyme is lost in translation.
A new website linked to Chanel 3 of the Iranian state TV, Varzesh 3 (Sports) reported in its live coverage: "The situation at the stadium is extremely volatile, you can hear loud slogans and horns and TV viewers are watching the match without sound, so they cannot realize what is going on at the stadium. This started after radical slogans were chanted from both sides and the state TV cut off audio broadcast, so the video coverage of the match continued in silence."
According to Varzesh 3, several football fans were wounded as the clash between the supporters of the two teams continued outside the stadium. Several others were arrested by anti-riot police, the report continued.
The Varzesh 3 report added that Tractor fans, complained about the police's behaviour and said a large number of the team's supporters were seriously wounded.
The website of the popular TV football show "90" reported in its live coverage, "There are currently some 65,000, fans from both sides at the stadium, and only three rows of seats separate the two excited contingents."
The match, which was one of the highlights of Iran's Super League, started after dark at 20:30 Tehran time, and ended with Tehran's Esteghlal winning the game 3-0.
The official news agency IRNA reported that stadium officials had allocated only 10 percent of the 100,000-seat stadium's capacity to Tractor fans. Angry fans clashed with the police and broke stadium seats and some window panes at the ticket office and attempted to cross the barriers to reach the additional platforms allocated to Esteghlal fans.
A Mehr news agency report titled "Serious clashes between Tractor fans and the police," says Tractor fans clashed with Police because far less seats were allocated to them.
According to Mehr, as the violence spread, the two teams' supporters threw seats at each other while also throwing bottles and stones into the court.
One day before this match, several fans and policemen were wounded in clashes at a stadium in Ahwaz while Khouzstan's Esteghlal was facing Tehran's Persepolis team. Reports say that some 10,000 security forces were called in to control the situation.
Chanting political slogans at stadiums, have been common in recent months following protest demonstrations that started in December 2017 and continued since.