The AFL and security services have had a significant scare as thousands of fans flooded into Melbourne’s Marvel Stadium for Saturday’s Bombers v Swans match.

A 15-year-old boy was flagged by security after trying to access the ground without a ticket, before the situation escalated quickly as he was found to be holding a knife on fake gun.

The teenager approached the entry gates at Marvel Stadium and was denied access before police were called to assist.

After being detained by officers he was then searched, before the knife and gun were discovered by nearby officers, who found he was carrying a small knife and a fake gun.

Victorian Police said they issued the youth with a caution after seizing the two prohibited items.

It is the second time the AFL has been rocked by a weapons incident after two men were allegedly caught with guns at a Carlton-Collingwood clash with more than 82,000 fans at the Melbourne Cricket Ground in April.

The weapons were discovered after the pair, who were on bail, refused a security request to leave the venue due to their behaviour.

Officials blamed the incident on a “breakdown” in screening measures.

With AAP.