CHICAGO (CBS) -- Public schools in Hammond, Indiana, were placed on lockdown for about two hours Wednesday morning, as police investigated a threatened shooting at Hammond High School. Police later determined there was no danger.

Hammond police said a social media post threatened gun violence at Hammond High School.

As a precaution, all public schools in Hammond were placed on temporary lockdown around 9:30 a.m. The lockdown was lifted around 11:30 a.m.

"At this time and we do not believe there to be any threat and school will continue as scheduled," police stated in a Facebook post.

Police earlier said they had identified the parties responsible for the threat.

An investigation continued Wednesday afternoon.