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.

Safeway employees at a Denver store walked out Monday, expanding a strike that started this weekend. The strike started small with workers at three stores in Estes Park, Fountain and Pueblo, and a Denver distribution center.

Safeway employees across Colorado have been going on strike, one union after another. And Tuesday, the strikes reached Grand Junction.

The union representing Safeway store employees in Colorado has given the required 72-hour notice that the strike is set to begin one minute before midnight on Sunday.