Four shop workers have been taken to hospital after being sprayed with a mystery chemical which brought them out in blisters.
Staff at a Co-op in Corby, Northants, were sprayed with the noxious substance after confronting two youths who were acting suspiciously.
One of the male youths confronted in the shop threw the substance at staff before fleeing the store.
The three women and one male staff member were taken to hospital with suspected chemical burns, which police said left their skin red and brought their mouths out in blisters.
Luckily, their injuries weren't serious and all four have since been discharged.
Northamptonshire Police said it was now actively seeking an "identified youth".
A spokesperson for the force said: "The incident happened at about 2.40pm [on Sunday, April 9], when staff at the Welland Vale Road Co-op in Corby confronted the pair after they were seen behaving suspiciously in the store.
"Paramedics and firefighters also attended the incident and all four victims were admitted to hospital for treatment before being later discharged.
"Police are carrying out forensic tests on the clothing to see if they can determine what the noxious substance was."
A spokesman for the force said that detectives were "actively seeking the arrest of an identified male youth" and urged anyone with information to contact Northamptonshire Police.
Central Co-op, which runs the store, told the Mirror: "We can confirm there was an incident at our Welland Vale Road store, in which four of our colleagues were taken to hospital.
"All colleagues have received the correct medical attention and have since been discharged.
"Police are continuing to investigate the incident and are attempting to find those responsible. The store continues to be closely monitored.
"Central Co-op takes these incidents incredibly seriously and will continue to support the colleagues and the store, along with the authorities in the ongoing investigation."
