Three teenage boys were rushed to hospital with burns after an attack in a Rotherham takeaway.
The boys were at Maranto's, High Street, Swallownest, when they had a liquid sprayed in their faces after an altercation with two men.
South Yorkshire Police said it is not yet know what the liquid was, but a mum of one of the victims, writing on Facebook, said the boys suffered 'burns'.
She said the liquid went into their eyes.
"All we can do it hope their sight is undamaged," she said.
A South Yorkshire Police spokeswoman said: "Police are making inquiries following a reported assault at a takeaway in Swallownest.
"It is reported that there was an altercation inside Maranto’s, High Street, between three teenagers and two unknown men.
"The two men are alleged to have sprayed a substance in the faces of the teens before leaving the premises.
"At this time, it is not clear what the substance is.
"Did you witness the altercation or see any suspicious activity?"
Anyone with information should call South Yorkshire Police on 101.