The stalemate between a contractor and employees continues at the Federal Law Enforcement Training Center in Artesia.
Fifty workers went on strike last week after Omni did not sign a new collective bargaining agreement.
These workers include groundskeepers and maintenance staff.
A union rep tells the Carlsbad Current-Argus that the NLRB has received a complaint accusing Omni of intimidation.
He also says the company has not provided employees with proper equipment.
The newspaper says it could not reach Omni for comment.