Part of the vehicle believed to have been driven by suspected killer Pol Cpl Panya Khamrab, left behind as he fled a child care centre in Na Klang district of Nong Bua Lamphu on Thursday.
Police said 31 people were confirmed killed by a former policeman who burst into a child care centre in Na Klang district of Nong Bua Lamphu on Thursday.
Many of the victims were reported to be children.
The child care centre is operated by the Uthai Sawan tambon administration organisation.
The man, who was identified as former Pol Cpl Panya Khamrab, was reportedly armed with guns and knives.
He forced his way into the centre and opened fire at the people inside.
Na Klang police station reported that the gunman was on the run.