Two boys, aged 12 and 15, have been arrested after a man was left with a fractured spine after being attacked with a metal bar.
The 54-year-old was hit "repeatedly" by four people on Sunday evening outside a Simply Fresh store in Northumberland Avenue, Reading, police said.
The victim was taken to the Royal Berkshire Hospital, where he remains in a serious but stable condition.
The boys were arrested on suspicion of GBH with intent.
Det Insp David Turton said: "The victim sustained considerable injuries in this brutal assault."
Thames Valley Police said the attackers all wore dark clothing and has asked for any witnesses to the assault, that happened at 21:10 BST, to contact them.