South San Antonio Independent School District has banned students from bringing backpacks, large purses, sling bags and messenger bags to school starting Monday, May 15.

The district’s last day of school is June 1. The move comes a week after Southwest ISD adopted a similar policy.

Small bags and clutches measuring 5½ inches by 8½ inches or smaller, clear bags measuring 12 inches by 6 inches by 12 inches or smaller, and 1-gallon clear zip-close freezer bags measuring 12 inches by 12 inches or smaller will be permitted under the new policy, which South San ISD announced on Twitter.

Students involved in extracurricular activities such as sports or band may bring a backpack, but it must be put away during designated times set by the campus, according to the post on social media.

Threats of violence at or against school campuses circulating on social media have been a persistent problem this year, although none have proved credible.

The Bexar County Sheriff has created a School Task Force with a focus on Southwest and Northside ISDs in response to a string of violent incidents in the surrounding area in recent months. The task force has made several arrests related to threats made against schools.