Metal detectors are being introduced at a college close to where three people were stabbed during a fight.
Sixteen people were arrested after a brawl outside Havering College
The victims, all aged 18, were injured outside Havering College in Hornchurch, east London, last month.
Head teacher Noel Ottley said more than £1m was being spent on increasing security and scanners were expected to be in place by Christmas.
On Wednesday, mayor Ken Livingstone said schools should install metal detectors to discourage knife carrying.
Mr Ottley said detector wands were being introduced as part of a package of measures which included police community support officers patrolling the grounds.
He said: "We can identify if anybody is carrying a weapon.
"We are also engaging more youth workers to retain students on the site during lunchtimes so they don't go into the local community making disruption for shops and neighbours."
Sixteen people, aged from late teens to over 40, were arrested after the brawl outside Havering College and bailed until later this month.
Knives were recovered by police near the scene of the fight and CCTV footage of the area is being examined by officers.
Havering College, which has about 14,000 students and offers further and higher education courses, confirmed one of the victims was a student there.