Three men have been arrested in connection with a suspected acid attack on a three-year-old boy in the English city Worcester.
The suspects, aged 22, 25 and 26, were detained in London on suspicion of conspiracy to commit grievous bodily harm, West Mercia Police said on Monday.
A 39-year-old man from Wolverhampton arrested on Sunday on suspicion of conspiracy to commit grievous bodily harm remains in custody, the force said.
The toddler was in a pushchair with his family in a shop when a corrosive substance was "thrown or sprayed" over him on Saturday afternoon, according to West Mercia Police.
He was treated in hospital for burns to his face and one arm before being released on Sunday afternoon.
Police said the long-term implications of his injuries were "uncertain".
Worcester City Council leader Marc Bayliss described the attack as "absolutely pure evil".
Worcester MP Robin Walker said the attack was "horrific", and that the "shock will be universal".
Police are continuing to appeal for information over the incident at Home Bargains in Tallow Hill.
