This happening early Wednesday morning and affects about 250 workers in all.
The members of United Food and Commercial Workers Local 1445 said it's in order to secure a fair deal that improves their lives and protects future workers.
The group also cites workers have still yet to see funds benefit the lives of its Maine employees following a merger between Hannaford's owner Delhaize and Ahold in 2016 and 4th quarter sales that rose to nearly $20 billion in 2017.
They said the strike comes after weeks of contract bargaining.
The former 3-year contract expired last Saturday.