SAN ANTONIO -

A fake grenade was found in a child's lunchbox Monday afternoon.

The grenade was found around 1:15 p.m. at Ott Elementary School in the 100 block of Grosenbacher Road, according to a statement issued by Northside Independent School District spokesman Pascual Gonzales.

He said school personnel evacuated the school.

NISD police were called out, along with the Bexar County Fire Department, and they determined that is was not a live grenade.

After nearly 35 minutes, student re-entered the school.

Parents were contacted by the school's "Robocall" system.

The incident is under investigation. Necessary disciplinary actions will be taken in accordance with NISD policies and procedures, Gonzales said.