Florida prisons were placed on lockdown Thursday following reports of security threats.

The Florida Department of Corrections announced that it canceled weekend visitation at all institutions for Saturday and Sunday because of a possible security threat.

Correction officials said they received information that indicated small groups of inmates at several institutions would try to disrupt prison operations.

The lockdown affects more than 97,000 inmates in Florida’s 151 correctional facilities, including major institutions, work camps and annex facilities. The move affects recreational and educational programs, but inmates are not confined to their cells, officials said.

The cancellation does not apply to work release centers, department officials said.