A young schoolboy found badly burnt on a canal bridge in Worcester may have been deliberately set alight.
John is being treated in a specialist burns unit
John Baldwin, 11, who was found in Bilford Road on Wednesday evening after calling for help, remains critically ill with burns to 30% of his body.
His mother Sandra said only a sick person could set a young boy on fire and then leave him.
Police said there was evidence fuel was used to set John alight, but they are still keeping an open mind.
Mrs Baldwin said: "Who could throw something flammable on a young lad in the street, set him on fire and then leave him?
"They must be sick. There is no other way to describe them than sick."
Mrs Baldwin said her son, who has two sisters - 10-year-old Catherine and Laura, nine, is a keen skateboarder who spends much of his spare time at the city's Perdiswell Skate Park.
Det Sgt Andy Price, who is leading the inquiry, said he had not ruled out the possibility the boy - known to most people as Johnny - was set alight by other children.
John may have been playing with other children
It is believed John had been playing with a group of youngsters on land nearby before he was hurt.
"We are keeping an open mind as to how John came by his injuries, but there is an indication that something such as an accelerant may have been thrown on him and then ignited," Det Sgt Price said.
"We think he may have been with other people, he may have been with other children - that's not confirmed yet.
"But he did manage to say that there was a 'they' there, when he was brought into hospital, so we work on the fact that there may have been other people.
"On the other hand, there is currently nothing to confirm that that is the case and there could have been a dreadful accident.
"At the moment, we are not able to talk to John about what really happened as he is sedated due to his condition. It could be some time before we can speak with him."
In the meantime, police are carrying out house-to-house inquiries in an effort to identify anybody who was with John before the incident.
He is currently being treated at a specialist paediatric burns unit at Morriston Hospital in Swansea.