A former policeman killed 34 people, including 22 children, in a gun rampage at a day-care centre in Thailand on Thursday, later shooting dead his wife and child at their home before turning his weapon on himself, police officials said.

The police identified the attacker as a former member of the force who was dismissed from his post last year over drug allegations.

The man had been facing trial on a drugs charge and had been in court in the hours before the shooting, a police spokesperson told broadcaster ThaiPBS.

He had come to collect his child from the day-care centre but opened fire when he did not find the child there, the spokesperson said.

District police official Chakkraphat Wichitvaidya cited witnesses as saying the gunman was also seen wielding a knife in the attack in Uthai Sawan, a town 500 km northeast of Bangkok in the province of Nong Bua Lamphu.

Paisal Luesomboon, a police spokesperson, also told ThaiPBS that witnesses reported seeing the attacker use a knife and a gun. “He started shooting, slashing, killing children at the Utai Sawan day-care centre,” Paisal said. About 30 children were at the facility when the attacker arrived, fewer than usual, as heavy rain had kept many people away, district official Jidapa Boonsom, who was working in a nearby office at the time, told Reuters.

“The shooter came in around lunchtime and shot four or five officials at the childcare centre first,” said Jidapa.

At first people thought the shots were fireworks, she said.

“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 forced his way into a locked room where children were sleeping, Jidapa said. She said she thought he killed children there with a knife, adding that a teacher who was eight months pregnant was also killed with a knife.

Videos posted on social media showed sheets covering what appeared to be the bodies of children lying in pools of blood. Reuters could not immediately authenticate the footage.

Prime Minister PrayuthChan-Ocha, in a statement on Facebook, called the shooting a “shocking incident”.

“I have ordered the police chief to travel to the scene immediately to take necessary actions and all involved parties to provide immediate relief to all affected people,” he said in the statement. Deputy Prime Minister PrawitWongsuwan will travel toUthai Sawan to visit the sceneon Thursday.