Four men armed with machetes assaulted a security guard at the elite Scots College in Bellevue Hill in an attempt to reach weaponry stored on the school grounds, police say.

The men confronted the guard on the school perimeter about 1am on Friday but failed to gain access to any building. It is understood the men demanded entry to an area where guns were stored but were refused by the guard.

Police are investigating an attempted raid on the weapons store at Scots College. Credit:Dallas Kilponen

The men fled in a car that was possibly driven by a woman, police said. The guard was not injured.

Scots College maintains target-shooting rifles on the property as part of its sport program, principal Ian Lambert said. The rifles have disabling mechanisms, making them incapable of firing except when used for practice or competition, he said.