Police have arrested six students from Rajamangala University of Technology's Uthen Thawai campus for allegedly killing two Pathumwan Institute of Technology (PIT) students on Friday.
The suspects killed the victims in an act of revenge for the killing of a female Uthen Thawai student in front of MBK shopping mall in Pathumwan late last month, police said.
On Friday evening, PIT students Chinapong Srikhacha, 18, and Polwat Chanwiset, 21, were shot dead while travelling on a motorcycle along Thoet Damri Road in Bang Sue district.
A Bangkok police source said the six Uthen Thawai students were arrested on Monday night and later confessed to Friday's attack.
The suspects were identified as Kabin Jirojmontri, 20, Panya Kemwatcharalert, 19, Attapol Yimanying, 20, Jirayuth Suwannachote, 20, Nattakorn Kamtaeng, 24, and Chitdilok Oumchu, 21.
Four are second-year students, while Mr Nattakorn and Mr Chitdlok are in their third year.
According to police, the second-year students were classmates of Kankanit Phromkaew, 20, the female student shot dead outside MBK on Aug 26.
The killing of Kankanit resulted in the suspects wanting to exact revenge on those who they thought were responsible for their friend's murder, police said. The suspects believed PIT students killed her.
The group was also involved in the murder of Patchara Kanpalasiri, 21, a Rajamangala University of Technology Krungthep student, who was shot in Soi Ramkhamhaeng 107 on Sept 1, police said. The suspects admitted killing Patchara because they thought he was a PIT student, police said.
Meanwhile, the parents of a 17-year-old student turned him in to police yesterday for allegedly shooting Bunyakorn Wattana-arporn, a third-year student at Rajamangala University of Technology Rattanakosin Poh Chang on a train in Bangkok last Friday. Mr Bunyakorn was seriously injured.
The suspect said he developed a dislike of Mr Bunyakorn after meeting him several times on a train and bought a pistol on the internet before shooting him, police said.