BANGKOK: World leaders have reacted to the news on the knife and gun rampage on Thursday that killed 37 people, including 22 children at a childcare centre in northeast Thailand.

British Prime Minister Liz Truss expressed her dismay over the tragedy at the childcare centre in Uthai Sawan in Nong Bua Lamphu province, about 500 km northeast of Bangkok.

"I am shocked to hear of the horrific events in Thailand this morning. My thoughts are with all those affected and the first responders. The UK stands with the Thai people at this terrible time," she tweeted.

Australian Prime Minister Anthony Albanese sent well wishes to the people affected by the incident.

"It's impossible to comprehend the heartbreak of this horrific news from Thailand. All Australians send their love and condolences," he tweeted.

The United States was horrified by the tragic shooting at the childcare centre on Thursday, United States' National Security Advisor Jake Sullivan said.

"The images are heartbreaking and our deepest condolences go out to the families who lost loved ones. We condemn this act of violence and stand ready to assist our long-standing ally Thailand in whatever they need," he said.

Malaysian Foreign Minister Datuk Seri Saifuddin Abdullah said Malaysians were shocked and deeply saddened to learn about the tragic loss of life and injuries following the horrible tragedy.

"Our deepest sympathies to the bereaved families and friends who lost their loved ones and we pray for the ones receiving treatment to recover safely," he tweeted.

Thailand Prime Minister Prayuth Chan o-cha said Thai national flags at all government premises would be lowered to half-mast on Friday following the tragedy.

The perpetrator a former policeman fled the scene in a vehicle and later killed his wife and son before fatally shooting himself.

Police said most of the 22 children aged between two to four years old were stabbed to death.

Meanwhile, the United Nations Children's Fund (UNICEF) too is saddened and shocked by the tragic incident.

In a statement, UNICEF urged members of the public and the media to refrain from posting or forwarding images and videos related to this violent incident, as it may further negatively impact children, victims' families, and their loved ones.

"Unicef condemns all forms of violence against children. No child should be a target or witness of violence anywhere, anytime.

"Early childhood development centres, schools and all learning spaces must be safe havens for young children to learn, play and grow during their most critical years.

"Unicef sends its heartfelt condolences and deepest sympathies to the families who lost loved ones and the injured. We join all people in Thailand in mourning and hope that those affected receive appropriate and timely support," it said.

-- BERNAMA