Sahuarita police investigating threat at Walden Grove High

"There have been NO shots fired," the department tweeted Thursday afternoon.

The threat came "via a picture of a 'grenade' received through an air drop or text message to possible a student(s)," the Sahuarita Police Department tweet said.

"Please stay off campus," police added, saying they are working to "address multiple claims and/0r rumors" and will provide information to the public as soon as possible.

Police said both uniformed and nonuniformed officers are at the school with its vice principal and others and emphasized their confirmation of no shots fired.