A three-year-old boy has suffered severe burns to his face and arm in a suspected acid attack in England that police believe was deliberate.
West Mercia police Chief Superintendent Mark Travis said investigators were working to identify the substance that burned the child on Saturday at a discount store in Worcester.
A 39-year-old man was arrested on suspicion of conspiracy to cause grievous bodily harm, while three others continue to be sought for questioning.
“At this time we are treating this as a deliberate attack,” Mr Travis said in a statement.
“The incident will rightly shock the local community, and I would like to reassure local people that we are carrying out a thorough investigation.”
Police released images taken from CCTV footage in a bid find the attacker.
“The three men in the photo may have information vital to our investigation,” Mr Travis said.
“I am sure someone will recognise them and I would urge anyone with information to contact us as a matter of urgency.”
Worcester City Council leader Marc Bayliss called the attack “absolutely pure evil”.
“Worcester is not that sort of place. We are a quintessential small English city,” he said.
“I have never heard of an acid attack in Worcester, so this is absolutely not something we have any experience of,” Mr Bayliss said
“We need to bring the perpetrators to justice and quickly.”
British police have reported an increase in acid attacks during the last year, but it is very rare for a victim to be so young. Some attacks are related to gang fights or late-night bar confrontations.
Most of the attacks have happened in London, but they have been reported in many parts of Britain. A London teenager was given a prison sentence of more than 10 years this year after being convicted of spraying acid into the faces of moped drivers so he could steal their mopeds.
Police also report that innocuous liquids sometimes are thrown into the face of mugging targets to make them think they have been hit with a corrosive substance, panic and give up their valuables more easily.