KNIFE GANGS LAY SIEGE TO SCHOOL.
Pupils were ordered back to their classrooms when the knife-wielding gangs of ex-pupils laid siege to Lenzie Academy, near Glasgow.
Rector Roderick McLelland ordered staff and pupils inside until police moved the youths on.
A knife was confiscated by police from an 18-year-old.
In a letter to parents, Mr McLelland said pupils were detained until police arrived because he was concerned about their safety.
He said: "There have been a number of confrontations involving local youths who had been loitering at the school gates, placing many pupils in a state of alarm and fear.
"In the light of the current situation, in consultation with the police I would strongly advise pupils should not loiter in the streets around lunchtime."
A police spokesman said: "Former pupils were noising up present ones and a nasty situation developed.
"The Rector took the correct action. Our officers in the area are keeping a close watch on the situation."