At least 31 people have been killed after a former police officer opened fire at a pre-school child daycare centre in Thailand, police say.

The gunman is still at large after the attack in Nong Bua Lamphu, in the north-east of the country.

Police say children and adults are among the casualties.

The attacker shot and stabbed children and adults and is now on the run, police said. A motive for the attack is unclear.

Reports in Thailand say the officer had recently been dismissed.

Police say he was last seen driving a white-four-door Toyota pick-up truck with Bangkok registration plates.

A senior police officer in Nong Bua Lamphu province said 23 children were among the casualties, AFP news agency reports.

Mass shootings in Thailand are rare. In 2020 a soldier killed 21 people and injured dozens more in the city of Nakhon Ratchasima.