Thousands of nurses in Minnesota were back on the job Friday after a tense return to their 14 hospitals, but neither side appeared any more ready to budge on the staffing issues that fueled the one-day walkout.

The nurses said the strike at 14 Minneapolis-area hospitals was motivated by their concern for patient safety. They have demanded strict nurse-patient ratios, something the hospitals call inflexible and unnecessary and say would increase costs without improving safety.

Nonetheless, the nurses believe they’ve made their point. The strike by 12,000 nurses forced the hospitals to bring in 2,800 temporary replacement nurses and additional nonunion staff while, in some cases, reducing the number of patients in their hospitals.

John Nemo, a spokesman for the Minnesota Nurses Association, said now it was time for the hospitals to stop “saying they want to negotiate and actually sit down and modify the contract offer our nurses resoundingly rejected nearly a month ago.” Hospitals spokeswoman Maureen Schriner said the proposal was “reasonable” and “the union needs to move toward serious negotiations.”

No new talks are scheduled and Nemo said future strikes are possible if the union can’t reach a deal to increase staffing. Nurses waiting in the rain outside Abbott Northwestern Hospital to return to work Friday morning said they were ready for another short walkout.

“I don’t think that’s a problem at all,” said Abbott nurse Andrea Fowler, but a longer strike would be a more difficult decision. “That I can’t say. That would be harder.”

Friday morning got off to a rocky start at Abbott and the Minneapolis hospital of Children’s Hospitals and Clinics of Minnesota when more than 70 nurses were turned away because they weren’t needed.

The hospitals have said for several days that not all of the union nurses would return on Friday because many hospitals reduced their patient populations ahead of the strike, mostly by rescheduling elective surgeries.

The nurses accused the hospitals of not following their contracts in handling the recall and promised to file complaints of unfair labor practices.

Schriner said no union nurses lost their job due to the strike. “It’s just a matter of when they get the call back,” she said.

She said the hospitals operated smoothly during the strike, with more than 230 surgeries performed or in progress and 44 babies delivered by 7 a.m. Friday, when the strike ended. The state Health Department had six of its nurses monitoring the hospitals, said department spokesman John Stieger, and they found no serious incidents.

Schriner said Friday that she didn’t know how much the strike cost the hospitals, but said it was far less than the $250 million a year the hospitals estimate they would have to spend if they accepted the union’s proposals for staffing.

Web advertisements from two large staffing agencies — Healthsource Global Staffing and U.S. Nursing — said they offered replacement nurses between $1,600 and $2,224 for one day of work and one day of orientation.

The union wants to write rigid staffing levels into their contracts, reduce the hospitals’ ability to “float” nurses from department to department and order hospitals to shut down units, with some exceptions, at 90 percent capacity in the name of patient safety. They also are resisting a proposal to reduce their pensions.

Schriner said the hospitals have an “excellent” safety record and said that Minnesota nurses are paid better, at $38 an hour, than the national average. The average Minnesota nurse, which includes full-time and part-time workers, makes about $62,500 a year

The hospitals’ latest proposal offers pay increases over the three-year contract of zero percent, 1 percent and 2 percent, with other increases for seniority. The union wants increases of 3.5 percent to 4 percent a year.