A brief but rowdy protest at the Nova Scotia Power headquarters on Tuesday is now the subject of an investigation by Halifax Regional Police.

Close to 200 union members, angry the company is looking at contracting out jobs, forced their way past security guards and into the downtown Halifax building at noon hour.

Halifax Regional Police spokeswoman Theresa Rath said they're looking into allegations that the scuffle lead to an assault.

“It’s our understanding at this point that there was group of protesters who tried to enter the building," she told CBC News.

"Security guards tried to keep them out, tried to keep the doors closed and when they were unable to do so protesters actually came through the doors and pushed the two security guards out of the way."

The power company has hired two off-duty police officers to provide security.

Tuesday’s protest was the second in as many days by union activists upset about outsourcing. On Monday the Federation of Labour protesters demonstrated outside an Emera briefing on its plans to import hydroelectricity into Nova Scotia from Labrador.