At least some of the victims were believed to be innocent bystanders hit when a gunman opened fire with a semi-automatic pistol during a chase on Saturday night. A witness said the gunman 'went mad, shooting indiscriminately'.
Police believe the shootings may have been triggered by a dispute involving rival drug gangs operating at the festival site in Somerset, where 80,000 have gathered for a weekend of music.
The victims, two of them women, were taken to Bath Royal United hospital by helicopter. Three were seriously hurt and two had surgery last night.
The shootings took place shortly after 10pm near the NME stage on the 600-acre festival site. Topping the bill on the stage were Icelandic singer Bjork and the group Orbital, while Elvis Costello was top of the bill on the other main stage.
Two men - a 30-year-old and a 26-year-old, both from London - were arrested on the site about 30 minutes after the shooting. The younger man was later released without charge on police bail.
By last night, 656 crimes had been reported and 211 arrests made, most for minor offences.