MINNEAPOLIS - Nearly 5,000 union nurses are on strike at five Allina facilities following a breakdown in contract talks over the weekend.

Both sides are braced for a long walkout by the Minnesota Nurses Association, which represents about 4,800 nurses at five Twin Cities-area hospitals run by Allina Health.

The open-ended strike began at 7 a.m. Monday, Labor Day, after a 22-hour bargaining session ended without agreement early Saturday.

Allina says it has brought in around 1,500 temporary nurses, and that it plans to operate the affected hospitals at normal capacity during the strike. Allina CEO Dr. Penny Wheeler says the hospitals will continue to deliver high-quality care.

The union's executive director, Rose Roach, says Allina is still seeking too many concessions on health insurance without adequately compensating nurses for the higher costs.

Besides health care, nurses say they need increased workplace safety and staffing.

The union says some progress was made, but that Allina said nurses' health care plans needed to end before 2020. Allina claims it "met the union more than half way on many issues."

MNA represents about 4,800 nurses at Abbott Northwestern and the Phillips Eye Institute in Minneapolis, United in St. Paul, Unity in Fridley and Mercy in Coon Rapids.