Leyland's Balshaw CE High isn't the only Lancashire school to be forced into a lockdown over the past 12 months.
A number of other schools have also been forced to implement their emergency security policies after receiving threats or have been involved in a high-profile incident.
These have included fears of intruders and bombs threats, or pupils bring weapons into schools.
Here are some of the incidents which have sparked fears among parents.
St Anne's Catholic Primary, Leyland
Read more>>> School goes into 'lockdown' after police incident outside
The primary school was put in ‘lockdown’ after an incident by its gates in November last year.
St Annes Catholic Primary, Slater Lane, Leyland, says it was not a major incident and that none of the children were in any danger.
Some parents had claimed an intruder was chased with police dogs and tasered.
But head teacher Liz Darnell said nothing of the kind happened at the school and described it as “a minor police incident”.
The head added: “Every school has formal lockdown rules if there’s something going on. If there was something going on near our premises I would make sure all our children are inside and go into lockdown.”
St Mary’s Catholic School, Leyland
Read more>>> Police called to Leyland school over knife claim
The school initiated its lockdown procedure last February after the knife claims - which were later found to be a false alarm.
Two teenagers who were not pupils at the school had gone to meet a pupil but were not found to have knives.
It was a traumatic event for children and teachers at the school as they were told to lock themselves into classrooms, barricade the doors and hide underneath desks.
Pupils were kept inside the school for over an hour, and when shaken children made their way out of the building, many were in tears.
The school confirmed that pupils and staff knew exactly what to do as they had practiced lockdown the term before.
Manor Road Primary School, Chorley
Read more>>> KNIFE CRIME: Boy, nine, has knife held to his throat at school
A Lancashire mum whose son was pinned to the ground by another pupil brandishing a knife says she believes many prefer to bury their heads and brush over issues.
Sacheen Leigh, who lives in Clayton-le-Woods near Chorley, was horrified when her son Ethan, who was nine at the time, came home from primary school to tell her he’d had a knife held to his neck by another boy.
Sacheen, who is a healthcare assistant and student nurse, ended up removing her son from the school after the incident last summer. Sacheen, who is married to Damian and has seven children of whom Ethan is the youngest, says: “I went to collect Ethan from school and the headteacher came over and told me that there had been an incident at lunchtime and it was nothing to worry about as it had been dealt with."
Karen Marshall, headteacher at Manor Road Primary School, said: “An incident took place last year at school which was dealt with quickly and safely and reported to the police. “I spoke to the parent on the same afternoon that this took place to make her aware of what had happened and the incident itself.
“Events like this are extremely rare in our school and are taken very seriously. ”The safety and security of our pupils is paramount and I’d like to reassure parents that we do not tolerate this type of behaviour.”
Read more>>> REVEALED: Shocking extent of knife crime in our schools
There were 18 permanent exclusions and 58 fixed period exclusions due to weapons in Lancashire schools during the 2016/17 academic year.
Figures disclosed by Lancashire County Council show during 2016/17, there were six permanent exclusions in Lancashire schools due to weapons - four were due to knives, one a pen-knife and one a BB gun.
The reasons given for the 24 fixed exclusions - where pupils are temporarily removed from school - six involved a dangerous weapon or object, four unknown or prohibited items, four a BB gun, one a catapult, two for laser pens, four for knives and three for pen knives.
During the previous year, 2015/16, there were 12 permanent exclusions at Lancashire schools involving weapons and 34 fixed period exclusions.