CVS pharmacy workers from seven stores in California went on strike on Friday, and they could be joined by about Rite Aid associates in the coming days.

The union represents nearly 7,000 CVS workers who are on strike to protest what leaders say are unlawful activities that have interfered with bargaining and prevented employees from reaching a

CVS pharmacy clerks and technicians walked off the job and onto picket lines at select locations Friday as their union pushes for a new contract and alleges unlawful labor practices, while store officials insisted they’ve negotiated in good faith and already reached tentative deals with the union on key issues.

CVS workers are on strike Friday and are planning on picketing and rallying at stores in Mid City, union leaders announced. Workers represented by United Food and Commercial Workers Local 770 in Southern California declared a strike at 7 a.