Officials said Wednesday a "first-of-its-kind" search turned up drugs and homemade weapons at the Nebraska State Penitentiary. 

The contraband was seized during a sweep of the prison by members of the Nebraska State Patrol, Lincoln Police Department, and Nebraska Department of Correctional Services. Several teams of investigators, SWAT members, and K-9 units combed the facility throughout the morning. 

NDCS Director Scott Frakes said the operation, which comes a week after the facility was placed on lockdown for similar searches, was planned more than a month in advance. 

“This was a first-of-its-kind operation for Nebraska’s prison system. It has been kept under wraps for weeks,” Frakes said in a press release. “It had to be, otherwise, the effectiveness would have been completely compromised.”

Frakes said inmates and staff members were notified that the penitentiary was going on lockdown, around 4:30 a.m. The facility is expected to return to normal operations by the end of the day Wednesday.