UPDATED AT 12:12 P.M. – Officials said Chatham High School was given the all-clear.

School district officials issued the following statement:

Earlier today, school administrators at Glenwood High School were alerted to a threatening message in regards to the school, that was posted on the app, Yik Yak. School administrators, safety and security staff, along with local law enforcement officers conducted a thorough search of the facility. No weapons or ammunition of any sort were found. The Ball-Chatham School District holds student and staff safety in its highest regard, and as such, will always enact its safety procedures with immediacy when circumstances warrant. Any person or persons found responsible for making a threat toward students, staff or any of our facilities will be prosecuted to the fullest extent of the law.

Ball-Chatham School District

CHATHAM, Ill. (WCIA) — Chatham High School students and staff were put on lockdown after police found that somebody threatened the school online.

The post was made on an app called YikYak. The app allows people to post anonymously, but police are able to trace the posts.

The police department has a person of interest that they are looking for regarding the post, and were searching the school Wednesday morning.

Chatham Police were made aware of the threat just after 9 am.

This comes after Springfield Police arrested three students Tuesday for threats to Springfield schools on YikYak.

Chatham Police will release more information as their investigation continues.