Some striking Providence nurses appeared unwilling to accept the tentative labor agreement reached with the health system this week, raising the possibility that the largest health care strike in Oregon history could continue into a fifth week.

An apparent breakthrough in the nearly month-long strike at Providence hospitals was reached Tuesday night as both Providence officials and the Oregon Nurses Association announced a tentative deal at all eight locations affected.

Providence and dozens of doctors at a hospital in Portland, Oregon, have reached a tentative agreement after 27 days of strike