A former police officer shot 24 children as they had a nap in a horrific massacre at a nursery.
He had been sacked before he went on a rampage with a gun and knife killing at least 38 dead.
He then shot his wife and son, who did not survive, before he took his own life at the daycare centre in Na Klang, Thailand.
The suspect has been named as ex-police lieutenant colonel Panya Khamrab who had been sacked from a nearby police station
He was armed with several weapons including a shotgun, a pistol and a knife.
Khamrab forced his way into the school at 12.30pm local time or 5.30am UK time and killed the kids one at a time before he fled the scene.
Police say he was "agitated" when after not finding his son at the centre.
A preschool teacher told how he stabbed the children and killed a member of staff who was six months pregnant.
Then 24 youngsters killed were aged between two to three years old.
But other victims included two teachers and a police officer who also died in the country's worst mass shooting.
The teacher said: "I knew it was a gun because I heard multiple gunshots, and then I saw him put in the bullets and point the gun at me.
"I called the teacher, and the teacher was hugging the child. He kicked the mirror and I climbed the walls and asked for help.
"He was inside the child centre for a long time. He used a knife and cut all the kids' heads. He was carrying a small gun.
"I didn't know he was going to kill the kids. I thought he was going to come out but he stayed inside a long time. He used a knife and stabbed all the kids."
Police say the killer drove home after the horrific attack and set fire to the vehicle before shooting his wife and child and finally himself.
Reports say there were 30 children in the centre when he broke into a locked room while they slept and went on a shooting and and stabbing spree.
His rampage continued outside and he rammed his van into bystanders and shot at them.
Images show bodies in bankets strewn across the nursery floor inside the building.
Families were shown weeping outside as ambulances took the injured to hospital.
The Mirror told earlier how Khamrab's motives were unclear but the fatalities included 24 children, as young as two years old, among 38 killed overall with 18 injured, a local police official said on Thursday.
District official Jidapa Boonsom said. "At first people thought it was fireworks.
"It's really shocking. We were very scared and running to hide once we knew it was shooting. So many children got killed, I've never seen anything like it.
The attacker was agitated when he arrived at the nursery to find his child was not there and left, Paisan Luesomboon, a police spokesperson, told Thai PBS television.
Police colonel Jakkapat Vijitraithay said the 34-year-old had been sacked from the force for drug use last year.
He had been in court on drugs charges before he went on the rampage.
Thai Prime Minister Prayuth Chan-ocha called the shooting a "shocking incident".
He said: "I would like to express my deepest condolences to the families of the lost and injured."
A police spokesman urged people to stop sharing pictures and clips of the victims of the shooting.
Police Major General Achayon Kraithong, a spokesman for the Royal Thai Police, said the incident was a loss that no one wanted to happen.
He continued: "First of all, I would like to express my condolences to all the bereaved families. including the injured and warn users of social networks to please refrain from sharing images and video clips."