Many people were injured during a milling brawl between rival technology college students that shut down a rock concert in Muang Thong Thani housing estate in Pak Kret district of Nonthaburi on Sunday night.
The ugly incident erupted about 8.30pm as about 3,000 people were gathering at a lakeside area that was the venue for a concert by the Ebola rock band and singer Pongsit "Pu" Kampee. The performance was to raise funds for rural students.
Suddenly large groups of teenagers armed with knives and wooden sticks, reportedly from Pathumthani Institute of Technology and Minburi Technical College, broke through the weapons checkpoint and began a brawl in front of the stage.
Concert goers fled, many were screaming.
About 100 police, soldiers and volunteers took about an hour to bring the situation under control. Many young people were seen to be bleeding, many with cuts to the head, reports said.
A 17-year-old identified as Withawas Leeta of Minburi Technical College was seriously injured, with a stab wound in his stomach.
Several teenagers were arrested for questioning and Pak Kret mayor Vichai Bandasak immediately cancelled the concert. He apologised to the concert goers and promised a refund of the 200 baht per ticket entry charge.