Security guards who patrol many of the Twin Cities' biggest companies plan a one-day strike this week.

The president of Service Employees International Union local 26 tells the Star Tribune the union is moving ahead with plans for a strike that could come as soon as Monday. Contract talks ended Friday and the union hopes the strike will bring their employers back to the negotiating table.

The local represents 2,000 guards who work for security contractors such as Allied Security and AlliedBarton. The Star Trib says those two companies supply more than half of the security guard market in the Twin Cities, including those who work at U.S. Bank, Wells Fargo, and Target.

Security officers voted to authorize a strike on February 9. They met Sunday at South High School in Minneapolis rally and discuss details of the strike.

Meanwhile, about 4,000 janitors reached a tentative contract agreement with about a dozen office cleaning companies. The janitors will get raises of $1.20 an hour over three years. Employers scrapped a plan to move about a thousand full-time janitors to part time status. The janitors will vote on the agreement later this week.