A grieving mother has paid tribute to her "irreplaceable" sons after the bodies of the two young brothers were found in a parked car.
The deaths of Paul Ross, six, and Jay Ross, two, are being investigated by Strathclyde Police who discovered the car, north of Glasgow, on Saturday.
The boys' mother, Giselle Ross, said: "Paul and Jay were beautiful boys who were well-loved by all the family and everyone who knew them. They did not deserve to die.
"Paul wasn't even allowed to play outside in case he came to any harm.
"Both boys loved their mum – they were real mummy's boys. They are irreplaceable and are greatly missed by all the family."
A man was found at the scene with severe burns. He remains in a critical condition in hospital.
Post-mortem examinations have been performed and police said the deaths were being treated as murder.
The boys, from the Royston area of Glasgow, were discovered late in the afternoon in a lay-by near the Campsie Fells beauty spot in East Dunbartonshire. Police have been searching area for evidence.
Elizabeth Davidson, the headteacher at Royston Primary School, where the older boy was a pupil, said: "Paul was a lovely, well-behaved, quiet young boy. I'm certain that children who knew Paul and his brother will be devastated when they learn of this tragic news. The school has been made aware of the incident and shall be supporting the mother in any way it can. Our thoughts and prayers are with her at this sad time."
Local people spoke of the shock at the deaths of the two boys, who lived in a flat with their mother.
The boys' father was estranged from Ms Ross, who lost her own mother a few months ago.
One neighbour said: "It's just so sad; it's a terrible thing to have happened. I live next door and my heart goes out to them."
Another woman said: "Words can't describe it. I used to see the mother passing by with the two wee boys, one of them in the pram. I think she must be in a terrible place.
"We were at mass on Sunday and everyone was talking about it.
"I didn't know the family well but I did know the grandmother quite well.
"The mother and grandmother were very close and the mum was devastated when she passed away, heartbroken. To bury your mum not long ago and then bury your two babies is just awful."
A neighbour of the boys' father, who lives in the Cowcaddens area of Glasgow, said he thought the man worked as a taxi driver.
"We used to see him around sometimes with the boys, usually about once a week," he added. "Everyone is in shock here, it is a horrible thing to have happened."
The lay-by where the boys were found is popular with visitors because of the views across Glasgow and its location near the Campsie hills. Flowers have been laid at the scene by well-wishers.
A spokeswoman for Strathclyde Police said yesterday: "We are following a positive line of inquiry."