Demanding immediate release of 13 students arrested by police during demonstration against the alleged molestation of a minor girl, Punjab Students Union (PSU) on Monday staged a protest here.The protesters assembled at old rest house (Darbar Ganj) where they held a rally in protest against the arrest of 13 students, including one girl on May 6 on alleged charge of causing damage to a private bus.The students on May 6 were protesting against the alleged molestation of a 13-year-old girl who was later thrown out of the bus along with her mother on April 29 near Moga. The minor girl had died on the spot whereas her mother was seriously injured.