NONG BUA LAMPHU, Thailand - The victims of one of Thailand's worst mass killings were accorded royally sponsored funeral rites, drawing hundreds of mourning relatives and friends to the beginning of three days of prayers on Saturday.

Last Friday, King Maha Vajiralongkorn, with Queen Suthida at his side, met relatives of the victims in a rare public interaction at Nong Bua Lamphu Hospital, where he offered his condolences.

"I come here to give you support. I am extremely sad for what has happened. I share your sorrow, your grief," he said in video footage released on Saturday. "There are no words that can express the sorrow. I support you all and wish you to be strong, so the spirits of the children can be at ease."

Holy water bestowed by the monarch was used to bathe the bodies, a customary ritual in Thai Buddhist funerals.

Colourful floral bouquets, juice bottles and toy cars were piled, in an outpouring of grief, on the lids of the 10 coffins at Wat Si Uthai in Nong Bua Lamphu's Na Klang district. It is one of three temples that will hold funeral rites.

Each coffin bore a framed photo of a child or adult who was killed by former policeman Panya Kamrab on Oct 6, when he stormed a childcare centre and shot at passers-by in the town of Uthai Sawan, 500km north-east of Bangkok, in the province of Nong Bua Lamphu.

Armed with a gun and knife, Panya, 34, shot and slashed at anyone who came in his path. Thirty-six people were killed, 24 of them children aged two to five.

The children were napping in three classrooms inside the building when witnesses heard what they thought was the sound of firecrackers some time after midday.

Childcare teacher Suphaporn Tarasi, 41, who was outside, witnessed what happened. "He shot at a group of technicians sitting outside the centre having their lunch. I started screaming for the teachers inside to close the doors and windows," she said.

When Panya dropped ammunition on the floor in trying to reload his 9mm pistol, Ms Suphaporn ran.

"I ran past the centre and hid in a bush. I could hear the children crying. Then it just stopped," she said as tears welled up in her eyes.

Ms Suphaporn hid for about 20 minutes, but preliminary investigations found that Panya was in and out of the centre in four minutes.

Among the victims were three-year-old twin brothers Veerapat and Voraphol Nuakhoa.

"They were so joyful and talkative. They were funny," said their mother Pimpha Thana, who said her only children died from knife injuries to their heads.

The safety officer and her husband will stay overnight at Ratsamakkee temple, which will also hold funeral rites for 20 other victims before they are cremated on Tuesday.

Meanwhile, local media reported that Panya's mother has found it hard to find a temple that will perform funeral rites for her son. He reportedly had a history of drug abuse and was fired from the police force in June for a drug-related charge.

On the day of the shooting, he had quarrelled with his wife and attended a court hearing. Local media said Panya then went to look for his son at the childcare centre but could not find him there, and launched the attack.

Fleeing the scene in his pickup truck, Panya continued his rampage, ramming into and shooting several passers-by as he drove to his home about 4km away. There, he shot and killed his wife and son before turning the gun on himself.

A neighbour, Phuwan Pholyeam, 29, saw Panya get out of his truck and run down the street with a gun in hand, shooting at two people.

"One of the men was shouting at others to run, and he was shot," said the housewife, who hid indoors with her three children and grandfather. She said his family had moved there about a year ago.

Stunned by the tragedy, the little-known town of Uthai Sawan has rallied around the families. Hundreds turned up at the Nong Bua Lamphu Hospital to donate blood as doctors rushed to save those shot and stabbed by the gunman.

One of them, three-year-old Sumaee, remains in the hospital's intensive care unit.

"Doctors say that he must fight for himself. I am cheering him on," said his mother Manaschaya Maewsuwan, 26, who runs a small general goods shop in her home.

Not all of the children were at the centre that day because of heavy rain. Serving 12 villages in the area with over 90 children at full attendance, it is now closed indefinitely.

Deputy chief of the Uthai Sawan local authority Chuanpit Keawthong said: "This was a peaceful community. Now that this has happened, I don't know what will happen to the children who come to the centre."