At least 24 of the 36 people shot or stabbed to death in the small town of Uthai Sawan were children.
On Friday morning, royal and government representatives stood in lines to lay wreaths at ceremonial tables in front of the Young Children’s Development Centre’s main door.
They were followed by weeping family members, who gathered their hands in prayer before laying white flowers on the wooden floor.
“I cried until I had no more tears coming out of my eyes. They are running through my heart,” said Seksan Sriraj (28) whose pregnant wife was a teacher at the centre and was due to give birth this month.
Seven of the 10 people who were wounded were being treated in hospital on Friday.
Thailand’s King Maha Vajiralongkorn and Queen Suthida were expected to visit two hospitals treating the wounded, and Prime Minster Prayuth Chan-ocha was expected to visit the nursery and the hospitals. A vigil was planned in a central Bangkok park.
Police speculated the gunman targeted the centre because it was near his home.
They identified him as Panya Kamrap (34) a former police sergeant fired earlier this year because of a drug charge involving methamphetamine. He had been due to appear in court on Friday.
Witnesses said the attacker got out of a car and shot a man and child in front of the building before walking toward the classroom.
Teachers at the child care centre locked the glass front door but the gunman shot and kicked his way through it.
The children, mainly two and three-year-olds, had been taking an afternoon nap.
Panya took his own life after killing his wife and child at home.
Nopparat Langkapin, a local official in Uthai Sawan, said the victims were “all children of our community”.
“Relatives, families and close friends are deeply saddened by this incident. And we all felt this across the community very quickly. Most of us are feeling depressed and sad because they are our children,” he said.
The attack took place in Nongbua Lamphu province, one of the country’s poorest regions.
In an interview with Amarin TV, Satita Boonsom, a childcare worker at the daycare centre, said the gunman after arriving at the scene shot a child and his father in front of the building before walking toward the classroom.
She said teachers inside locked the door but he forced his way in and attacked the children and teachers with a knife and firearm.
She said the centre usually has around 70 to 80 children but there were fewer at the time of the attack because the semester was closed for older children.
“They wouldn’t have survived,” she said.
Mass shootings are rare but not unheard of in Thailand, which has one of the highest civilian gun ownership rates in Asia, with 15.1 weapons per 100 population compared to only 0.3 in Singapore and 0.25 in Japan.
That is still far lower than the US rate of 120.5 per 100 people, according to a 2017 survey by Australia’s GunPolicy.org non-profit organisation.
The US and Australia expressed sympathy and solidarity.
“All Australians send their love and condolences,” Australian Prime Minister Anthony Albanese tweeted.
“This violence is both senseless and heart-breaking,” US Secretary of State Antony Blinken said.