Striking teachers hold a rally outside Oakland's City Hall on Thursday.
CNN  — 

Public school educators in Oakland, California, went on strike Thursday after contract negotiations in which they’re seeking higher pay and more efforts to address social concerns failed to yield a deal – and the strike is set to extend into Friday, the district said.

Oakland Unified School District schools still were open to the district’s roughly 34,000 students Thursday and will be throughout the strike unless otherwise announced, with principals and office staff helping educate and supervise them, district officials have said.

The strike – the second in four years in Oakland – includes teachers, counselors and others represented by the Oakland Education Association, which has said it is seeking, in part, pay that would bring salaries up to the county median.

Strikers Thursday set up picket lines outside Oakland schools and gathered for a rally outside city hall.

“Our goal … is to bargain a contract that will help the (district) recruit and retain good teachers and provide our … students with much-needed services,” said union president Ismael Armendariz. “We’re not going to just go along to get along. If the district won’t respect and fulfill the urgent needs of students and teachers they should expect resistance.”

The strike comes less than two months after school workers in Los Angeles carried out a three-day strike to secure higher pay, more full-time work and increased staffing levels. Both work stoppages are among a wave of school strikes across the country, sparked by complaints of dilapidated school conditions, insufficient funding and low pay, among other issues.

In Oakland, the strike comes with just three weeks left in the district’s school year. The last Oakland educators’ strike, in 2019, lasted seven days.

In a message to parents on Thursday, the district said the strike would extend into Friday.

District says its pay offer leaves little left for other issues

The district says its latest proposal would give teachers what it calls an unprecedented raise. The proposal would give a retroactive 10% raise to all union members, and teachers in particular would see a 13% to 22% jump in salary from this year to next, along with a $5,000 bonus, the district says.

The pay scale adjustment would let the most experienced teachers collect an annual salary of as much as $109,746, the district says.

The union has said it is pushing the district to provide improved services for students with disabilities; offer more mental health support for students recovering from the Covid-19 pandemic; and invest in historically Black community schools.

The union also wants to use what it calls the district’s excess land to house homeless students, it told CNN last month.

The district’s superintendent told reporters Thursday that because so much of the budget is focused on teacher salaries to retain them, “there is very little remaining resources to address other issues.”

“While we agree with most of the underlying principles of the common good, there are many other ways to collaborate with (union) in this area,” said Superintendent Kyla Johnson-Trammell. “We would have preferred to spend the last two days focused on how best to reach and agreement to retain our educators.”

“As a district, we simply can’t do everything,” Johnson-Trammell said.

“It’s going to take far more than just the district to really have some serious solutions,” said district labor director Jenine Lindsey.

On Thursday, the union claimed it learned the school board did not give district officials full authority to bargain with the union. “It has been really deeply frustrating to get to this point after seven months of bargaining,” a member of the union’s executive board, Vilma Serrano, told CNN.

When asked for comment, a district spokesperson referred CNN to the district’s Thursday evening message to parents.

The message, in part, addresses the union’s demands on social issues.

“It’s important to remember that these topics are not mandatory subjects of bargaining. We want to discuss these important topics, but we want to do so when the topics should be discussed - as part of a board-led policy discussion,” the message reads. “While we agree that the issues raised … are important, this discussion should not hold up an agreement on significant pay increases.”

Both the district and the union announced Wednesday night that educators would start striking Thursday. Both sides spent seven “long days and nights” bargaining before the strike, the district said Wednesday.

CNN’s Tina Burnside contributed to this report.