Damage to a window at York University's main campus was originally thought to be the result of a bullet hole but police now say it appears to have been caused by a bottle.

Police responded to the Scott Library at York on Monday morning at around noon after reports of damage caused by a bullet.

Police tweeted that they were responding to a shooting, but later clarified that they were not sure when the damage to the window occurred and said they could not confirm what caused it. However, they did say the damage did not appear to be from a bullet.

York University later said in a tweet that the damage was caused by a bottle.

Authorities are trying to determine when exactly the window was damaged.

No injuries have been reported.