Staff at the school in the north of the city managed to hold back the two men who entered the school on Tuesday morning.
The student they were looking for had apparently kicked the door of their car after it almost ran him over near the school.
After the incident, the boy was chased by six men, two of whom managed to enter the school with a machete and a handgun.
The two men left the property, shouting obscenities and threatening to kill those who got in their way, after school staff and pupils made it clear they were not going to find the boy.
The boy in question hid in the headteacher’s office until the men had gone.
Police are still searching for the men involved.