The group's president Ziad Albidani told Spanish sports daily AS the attack happened towards the end of the match before the penalty shoot-out decided by Cristiano Ronaldo.
The number of dead has been put at 12 with eight injured. The extent of their injuries are not known.The terrorists, believed to be ISIS members, fled and have yet to be captured. All the victims, said to be aged between 18 and 30, are thought to be Iraqi nationals.