Allina Health said Monday that employees are performing with professionalism and compassion at its five Twin Cities hospitals where nurses are on strike, but the nurses union said it is collecting reports of patient care problems and will assist in reporting them to state regulators.

Standing at the picket headquarters across from Allina’s flagship hospital, Abbott Northwestern in Minneapolis, union officials said employees who are on the job have reported instances of delayed care, closed units that were supposed to remain open and confusion in the search for supplies.

“We will be asking our regulatory agencies here in Minnesota … to be looking into these situations in order to protect Minnesota patients,” said Mat Keller, a regulatory and policy specialist for the Minnesota Nurses Association (MNA).

Patient care was transferred to 1,400 replacement nurses at 7 a.m. Sunday, when roughly 4,800 MNA nurses walked out to start a seven-day strike at Abbott, United Hospital in St. Paul, Mercy Hospital in Coon Rapids, Unity Hospital in Fridley and Phillips Eye Institute in Minneapolis.

While acknowledging that two surgical recovery units at Abbott have closed for the week as part of strike preparations, along with United’s rehabilitation unit, Allina officials said the bulk of patient care is continuing as usual and that doctors and other staff have been pleased with the replacement nurses.

As of Monday afternoon, the Allina hospitals had more than 900 patients admitted. The hospitals also treated 640 emergency room patients — a typical number — though Abbott’s ER was so busy at one point Sunday night that it had to divert ambulances to other hospitals.

Abbott’s president, Dr. Ben Bache-Wiig, said he knew of no unusual delays in care due to the strike, and that elective surgeries were taking place as scheduled.

“We make a promise every day to our patients,” he said, “that we will deliver safe and high quality care.”

Allina and the MNA have stalemated over a new three-year contract, with negotiations stuck over the health system’s demand that nurses phase out of their expensive union-backed health plans and transition to the company’s health insurance.

Union leaders said 2,000 nurses were scheduled to picket Monday, more than turned out on Sunday at the start of the strike.

One nurse said she was circling around 7 a.m. Monday with nursing colleagues when she received a surprise text; it was from an apologetic manager who couldn’t find an IV tray that had been locked in storage overnight.

MNA officials cited her case and said any complaints rising to the level of regulatory violations would be reported; the Minnesota Department of Health regulates hospitals and the Minnesota Board of Nursing handles nurses.

Allina officials expressed disappointment at the claims, and at the nurses’ insistence on preserving union health insurance plans that, Allina says, are out of step with health plans today. Allina contends that the nurses’ insurance will be subject to a federal “Cadillac” tax on high-cost plans by 2020 and says that switching all nurses to the plans that cover other Allina employees would save $10 million per year, money it could put toward improved patient care.

That amount “means a whole lot to what service we’re able to provide,” said Dr. Penny Wheeler, Allina’s chief executive, noting it could expand cancer care coordination, mental illness support and end-of-life care services.

Talks broke off June 13, though negotiators met late last week to establish how Allina will call nurses back to work when the strike ends on Sunday. The health system doesn’t have to call all nurses back immediately if the hospitals have low patient numbers. That could be a particular concern for nurses at Unity, which condensed some patient units and is operating at minimal capacity for the week.