Thousands of University of California academic staff who went on strike across six campuses to protest administrators’ response to pro-Palestinian protests returned to work on Monday under a court order, but their union vowed to stage more protests in the future.

An Orange County Superior Court judge late Friday approved a temporary restraining order sought by the university, saying the strike stemmed from non-labor issues and was in violation of a no-strike provision in the union’s contract.

University officials originally petitioned the California Public Employment Relations Board, but the panel twice denied their request for an injunction.

During pro-Palestinian protests in recent weeks, unionized academic researchers, graduate teaching assistants and post-doctoral scholars walked off the job in protest of unfair labor practices at the university.

The strike was organized by United Auto Workers Union Local 4811, which represents about 48,000 non-tenured academic employees at 10 UC campuses and Lawrence Berkeley National Laboratory.

The protest strike began on May 20 at the UC Santa Cruz campus, and over the next two weeks spread to campuses at UCLA, UC Davis near Sacramento, and in San Diego, Santa Barbara and Irvine. There are about 31,500 UAW members across these six campuses. There are 10 campuses in total in the UC system.

Melissa Matella, UC’s associate vice president for labor relations, welcomed the restraining order, saying in a statement that continuing the strike “would have caused irreversible damage to students’ academic achievements and halted important research projects in the final quarter.”

Judge Randall Sherman set a hearing for June 27 to hear arguments on whether to extend the injunction. The union’s permit to strike expires June 30.

UAW 4811 leaders denounced the decision, saying the judge had exceeded the authority of the Employment Relations Board by intervening in a labor case outside the court’s jurisdiction.

Still, the union said its members were complying with the court order. The UAW said it will focus its attention on upcoming grievance proceedings against the university.

Among other things, the union is demanding amnesty for graduate students and other academic staff who were arrested or face discipline for their roles in campus protests against Israel’s military assault on the besieged Palestinian territory of Gaza.

The strike was the first union-backed protest to show solidarity with a rise in pro-Palestinian student activism on dozens of US campuses in recent months.

The UAW said it plans additional protests at UC Davis on Tuesday and at UCLA on Wednesday.

Union leaders have said the main reason behind the strike was the arrest of 210 people, including graduate students working on campus, at the site of a Palestinian solidarity protest camp demolished by police at UCLA on May 2.

Masked assailants armed with sticks and rods had attacked the camp and its residents the night before, triggering bloody clashes that continued for at least three hours before the police restored peace.