Pol Capt Anon Sajuntheuk, on duty at Mueang police station, said the accident occurred at 2.30am at the intersection outside Bangkok Ratchasima Hospital on Mittraparp Road.
Anon said Chaiya Nisida, 48, the driver of the bus travelling to Bueng Kan, did not see the three vehicles waiting at the traffic light due to heavy rain and crashed into them.
It wasn’t immediately clear whether the people injured were on the bus or in the vehicles it struck.
The bus had been scheduled to stop at the Nakhon Ratchasima terminal on its way further northeast.