Metropolitan Police Division 2 commander Pol Maj General Ekachai Boonvisut held a press conference on Sunday to announce the arrests in the murder of Witcha Noo-udom, who was studying at the College of Industrial Technology at King Mongkut’s University of Technology North Bangkok.
The 11 males are to be charged with murder and assault.
The four girls, ages 16 and 17, are friends with those arrested, who were in their first to third years at another technological college.
Witcha was walking with two friends from a restaurant in Soi Wong Sawang 11 in Bang Sue district towards their apartment nearby just after midnight Saturday when 11 young men on seven motorcycles attacked them, most using their helmets as weapons.
Witcha was fatally stabbed in the neck. His friends were injured.
A 16-year-old is alleged to have stabbed Witcha, at which point the assailants quickly dispersed.
Ekkachai said the teen with the knife told police he disposed of it at a road island near Big C Wong Sawang.
Ekkachai said police determined the attackers had been drinking together elsewhere in the lane and exchanged abusive words with a group of teenage pedestrians.
They saw Witcha and his friends emerge from the restaurant and mistakenly believed they were scolding them, leading to the attack.