The Asian Football Confederation is investigating reports that a firecracker was thrown during a champions league match in Iran between Saudi Arabian club Al Ahli and Sepahan.The governing body of Asian football said in a statement Monday that the match commissioner reported that several objects were thrown toward an assistant referee during Wednesday's 0-0 draw in Tehran, including a firecracker. One of the objects exploded which prompted referees to stop the match for several minutes. No one was injured.A video of the incident showed a Sepahan player picking up one of the objects and tossing it away seconds before it exploded. Several media outlets reported that it was a grenade which was denied by the AFC.