The demonstration took place just days before Iran is scheduled to face New Zealand in its opening Group Stage fixture on 15 June in Los Angeles.
Protesters said they wanted to draw attention to ongoing political and human rights concerns in Iran, while also expressing opposition to what they described as the Iranian national team's ties to the Islamic Republic.
The gathering came amid controversy over FIFA's reported decision to prohibit the "Lion and Sun" flag from being displayed inside World Cup venues.
The flag, associated with Iran before the 1979 Islamic Revolution, has become a symbol for many opposition groups and members of the Iranian diaspora.
