Three people are in custody after police say a replica gun was brought into a Scarborough high school on Thursday morning.

Toronto police said they were first alerted to the reports of a gun inside Albert Campbell Collegiate shortly after 9 a.m. and “responded quickly.”

The school, located on Sandhurst Circle near Finch Avenue East, was placed in lockdown while officers investigated.

A replica gun was recovered a short time later.

Const. David Hopkinson said three people are in custody in connection with the incident. Their ages were not immediately provided.

There was no word on whether charges, if any, will be laid.

The lockdown has since been lifted.

“All students are safe and accounted for,” police wrote in a tweet.