Thai Prime Minister Prayuth Chan-ocha on Monday ordered law enforcement agencies to tighten gun ownership rules and crack down on drug use following a mass killing by an ex-policeman at a daycare centre that left has the nation in shock.

A total of 36 people including 24 children were killed in a knife and gun rampage last week by an ex-cop who later killed himself in Uthai Sawan, a town 500 km (310 miles) northeast of Bangkok. It was one of the worst child death tolls in a massacre by a single killer in recent history.

Prayuth has instructed authorities to proactively search and test for the use of illicit drugs among officials and communities, and step up treatment for addicts, government spokesperson Anucha Burapachaisri said in a statement.

The prime minister has ordered government registrars to revoke the gun licenses of registered owners who have reportedly behaved in a way that "threatens society" and "creates chaos or causes unrest", Anucha said, alongside a crackdown on illegal gun sales, weapons smuggling, and the use of illegal firearms.

Thai authorities plan to recall guns from officials and police officers who have misused their firearms or have behaved aggressively on duty.

Regular mental health checks will also be required for gun license applicants and holder, Police Chief Police General Damrongsak Kittprapas told reporters.

Gun ownership is high in Thailand compared with some other countries in Southeast Asia. Illegal weapons, many brought in from strife-torn countries, are common.