Hamilton police say several threats in schools are being investigated in the city.

The threats involve messages written on bathroom stalls over the past few days.

Police tell CHCH News say threats made at Westdale Secondary School, St. Jean De Brebeuf Catholic High School, and Bishop Tonnos Cathlic Secondary School are included in their investigation.

Investigations found threats at Hillcrest Elementary to be unsubstantiated.

A student at Bennetto Elementary brought a pellet gun to school yesterday. It was not used, but police were at the school for support.

A letter received by parents reveal officials at Bishop Tonnos were made aware of a threat last Friday, leading to an increased police presence.