A 22-wheeled truck smashed into 16 other vehicles on Bangkok's southern ring road in Phra Pradaeng district on Sunday evening.
Rescue workers were told of the accident on the Bang Phli-Suksawat section of Kanchanaphisek Road about 5pm on Sunday.
The section of the road was closed for about an hour as rescue workers took injured people to hospitals and police removed damaged vehicles.
The incident caused several kilometres of traffic congestion heading for Pak Nam and Bang Na areas. The road was partly reopened about 6.30pm on Sunday.
One driver whose car was among the damaged vehicles said traffic was slowing down on the road and suddenly the big truck smashed into many vehicles including cars, pickup trucks and a gas truck.
Police were investigating the cause of the accident.
