Police in Catania were on Wednesday studying video footage believed to be crucial in the hunt for the killer of Filippo Raciti, the policeman slain during riots at a soccer derby in the city.
The film shows a young fan apparently hitting Raciti with a wash basin ripped out of the lavatories in the north end of the Catania soccer stadium.
Police are working to identify the attacker but their task is made difficult by the smoke from flares which often obscures the scene and the fact that the fan has his face partially covered.
During the night police arrested another five minors and an adult believed to have been involved in the rioting which led to Raciti's death at the Catania-Palermo match last Friday.
All six were identified thanks to film footage and photos of the disturbances outside the Catania stadium.
The fresh arrests take the total number of fans handcuffed in the investigation to 40. Sixteen of those who have been detained are minors.
So far no one has been directly accused of killing the policeman, the head of the Catania police's flying squad Giovanni Signer said.
Police continue to focus their attention on a group of young fans believed to have come into contact with Raciti outside the stadium.
Raciti - the first policeman to die in decades of stadium violence - died from internal injuries as fans fought police with metal bars and powerful firecrackers.
According to the investigation, the policeman was attacked by a group of fans at around 19.20, during the second half of the soccer match. One of the assailants hit him in the abdomen.
Not realising the seriousness of his injury, he continued his work outside the stadium and 50 minutes later was inside a police car when rioting intensified and firecrackers were thrown.
According to the reconstruction, Raciti then emerged from the car, a paper bomb exploded and he sank to the ground. Investigators say it took this long for the effect of his injury to become apparent.
He died later in hospital of liver injuries.
