Armed thugs have invaded the premises of the Nigeria Labour Congress (NLC) in Kaduna State.
The armed men numbering about 100 occupied the secretariat, which is the meeting point of the ongoing 5-day warning strike.
The thugs were, however, stopped by a police detachment while 20 of them were arrested.
The police Public Relations Officer, ASP Muhammad Jalige, confirmed the arrest, saying security personnel have been deployed to avert break down of law and order.