Six people have now been arrested after a knife-wielding group of males started threatening students at a college in Lancashire.
Police said the targeted attack at Runshaw College in Leyland resulted in a 17-year-old boy being nicked on the arm.
He was taken to hospital but his injury was not thought to be life-threatening.
A member of staff at the school had received an anonymous report at 10.40am on Monday saying that a group of people with weapons were going to travel from Manchester to the college.
Lancashire Police said officers were sent to the college and just before 4pm they saw a group of males walk onto the property as students were leaving.
Some of the group were seen carrying knives and were making threats towards students, a police spokesman said.
The group tried to escape when they saw police but three people sitting inside a Nissan Micra nearby were arrested, along with a fourth person who tried to run away.
A fifth person was arrested after a second vehicle, a Peugeot 306, was stopped on the M55.
A sixth arrest was made on Monday evening.
Chief Inspector Gary Crowe from Leyland Police said: We know that this disorder is related to a personal issue between two members of each group.
There is nothing to suggest there are any further fights planned however, if you know different, you must let us know.
Thankfully only one person suffered a minor injury but it could have been much worse.
To those who think it is acceptable to behave like violent thugs, my message is clear: You are not welcome in Leyland and we do not tolerate this kind of shocking, deplorable behaviour.
He appealed for anyone with information or phone footage relating to the incident to contact police.
The college said on Twitter that there had been an incident but classes on Tuesday would go ahead as usual.
The incident comes after two teenagers were killed in separate stabbings on Friday and Saturday evening, bringing the number of victims this year to at least 35.