Following the attack, gunman Panya Khamrab went home and killed his wife and child before taking his own life, police said.

Armed with a shotgun, pistol and knife, Khamrab opened fire on the childcare centre in northeastern Nong Bua Lam Phu province at about 12:30 pm (0530 GMT).

Police Colonel Jakkapat Vijitraithaya from the province where the attack happened told AFP that the gunman killed 35 people, including 23 children, and wounded 12 others.

The 34-year-old former police lieutenant colonel had been dismissed from the force last year for drug use, Vijitraithaya added.

Eyewitness Paweena Purichan, 31, was riding her motorcycle to her shop when she encountered the fleeing Panya driving erratically.

He intended to crash into others on the road,“ she told AFP.

The attacker rammed a motorbike and two people were injured. I sped off to get away from him.

“There was blood everywhere.”

Paweena said the attacker was well known in the area as a drug addict.

Video footage after the incident showed distraught parents weeping in a shelter outside the nursery, a yellow-walled single-storey building set in a garden.

Thai Prime Minister Prayut Chan-O-Cha said he had ordered the national police chief to “fast-track an investigation”.

Concerning this horrifying incident… I would like to express my deepest sorrow and condolences to the families of the dead and injured,“ Prayut wrote on his official Facebook page.

Thailand forms part of Southeast Asia’s so-called Golden Triangle which has long been an infamous hotspot for the trafficking and abuse of drugs.

Surging supplies of methamphetamine have sent street prices crashing in Thailand to all-time lows, according to the UN Office on Drugs and Crime.

Mass shootings rare

The mass killing comes less than a month after a serving army officer shot dead two colleagues at a military training base in the capital Bangkok.

While Thailand has high rates of gun ownership, mass shootings are extremely rare.

But in the past year, there have been at least two other cases of shooting murders by serving soldiers, according to the Bangkok Post.

In 2020, in one of the kingdom’s deadliest incidents in recent years, a soldier gunned down 29 people in a 17-hour rampage and wounded scores more before he was shot dead by commandos.

That mass shooting, linked to a debt dispute between gunman Sergeant-Major Jakrapanth Thomma and a senior officer, triggered public anger against the military.

The soldier was able to steal assault rifles from an army depot before embarking on his killing spree, posting live updates on social media as he did so.

Military top brass were at pains to portray the killer as a rogue soldier.