The union said that a cache of 30 "shanks," or homemade knives, was found in a broom closet and a cell at the prison.

A spokeswoman for the Department of Rehabilitation and Correction acknowledged that weapons were found, but she said the number was less than half what was reported by the union.

The Ohio Civil Service Employees Association set up an informational picket line and called for a prisoner lockdown yesterday to protest "dangerous conditions" at the Mansfield prison.

The union also said that there were 43 assaults by inmates on staff members in the past three months, an all-time high for the prison.

However, state spokeswoman Julie Walburn said there were 16 assaults, none of them resulting in serious injury, over the same period.

"We aren't minimizing the severity of those assaults," Walburn said. "But we don't see any reason to believe this institution has more problems than any other Level 3 institution."

Level 3 prisons house prisoners convicted of the most serious crimes.

Walburn said the source of homemade weapons is being investigated. If any inmates are found responsible, they could face new criminal charges.

Douglas Mosier, the union's chapter president at Mansfield, said gang activity involving younger inmates is running rampant.

"We're so short of staff up here, and it's not just officers," Mosier said.

The union represents about 470 employees at Mansfield and 9,800 in the entire prison system.

Walburn acknowledged that the prison is down about 25 officers, but half of the slots are to be filled in the near future.

Ohio prisons are holding about 51,000 inmates or 32 percent above normal capacity.

The prisons department also is eliminating positions and closing some programs to cut its two-year budget by $87.2 million.

Information from the Associated Press was included in this story.

ajohnson@dispatch.com