Around 70 supporters of the Basque team were set upon by 80 people, presumably Lazio fans, ahead of Thursday's Europa League match between the teams.

In total nine fans were injured, including three who suffered stab wounds.

The most seriously injured person is said not to be in a life-threatening condition.

The other two in hospital are expected to recover within 30 days and 12 days.

Three other fans were discharged after treatment while three more left the emergency room before being examined.

Police seized clubs, chains, hammers and other tools used in the attack at the scene of the assault.

ANSA