Safeway workers in several Colorado cities entered the third day of labor strikes Tuesday against Safeway and Albertsons over alleged unfair labor practices, with picketing in Grand Junction prompting a temporary store closure.

Workers in Estes Park, Fountain, two in Pueblo, and a Safeway distribution center in Denver, walked out on Sunday and were joined by employees from Castle Rock and the Littleton location on Mineral Ave on Monday.

Workers at Albertsons, Pavilions, Ralphs and Vons grocery stores will begin preparations on Thursday for a possible strike.