Five people have been arrested after a gang of males armed with knives entered the grounds of a college and threatened students.
Staff at Runshaw College in Leyland, Lancashire, rang police on Monday at 10.40am after they received an anonymous report stating a group with weapons were heading to the college by train from Manchester.
Officers were sent to the site and shortly before 4pm they witnessed a group of males walking into the grounds while students were leaving.
Some of the group were seen carrying knives and making threats towards students, said Lancashire Police.
A 17-year-old boy was nicked on the arm during the incident and has been taken to Chorley Hospital.
His injury is not thought to be serious.
No-one else was injured during the incident, police added.