Iran has warned the U.S. that it will carry out “devastating” and “crushing” revenge after it accused the country of being involved in an attack on a military parade over the weekend that killed 25. The deputy head of Iran’s Revolutionary Guards warned both U.S. and Israeli leaders Monday that it will seek vengeance for the deaths, which included 12 members of the Revolutionary Guards. “You have seen our revenge before... You will see that our response will be crushing and devastating and you will regret what you have done,” Hossein Salami said on state television. Many chanted “death to Israel and America” as thousands gathered in the southwestern Iranian city of Ahvaz to mourn victims. Four attackers fired on a viewing stand where officials gathered to watch an annual event marking the start of the Islamic Republic’s 1980-88 war with Iraq.