A former policeman killed 34 people, including 23 children, during a knife and gun rampage at a day care center in northeastern Thailand on Thursday, police said, before later shooting dead his wife and child at home and turning his weapon on himself.

In one of the world's worst child death tolls in a massacre by a single killer in recent history, most of the children who died at the day care center in Uthai Sawan, a town 500 kilometers northeast of Bangkok, were stabbed to death, police said.

The age range of children at the day care center was from 2 to 5 years, a local official told Reuters.