Striking teachers rally in downtown Chicago. (Ashlee Rezin Garcia/AP)

Thousands of teachers are expected to remain on strike Thursday as the city enters the second week of a job action that is keeping 300,000 schoolchildren out of class in the nation’s third-largest school district.

About 20,000 teachers and several thousand school staff members went on strike a week ago, fighting for wage increases and other changes. They want a commitment from the city to hire additional staff — including classroom aides, nurses and social workers. And they want the city to hire more teachers so class sizes can be reduced.

The strike by Chicago teachers finds echoes in job actions that have swept school systems from West Virginia to California since February 2018.

Chicago teachers also want the city to tackle many of the symptoms of poverty that have made it difficult for their students to learn, including trauma and homelessness. They hope to compel the hiring of more teachers and classroom aides of color so that the school workforce can better reflect the district’s diversity.

Mayor Lori Lightfoot, who won a landslide election in April, is showing signs of impatience with the union. On Monday, she and Janice K. Jackson, chief executive of Chicago Public Schools, sent a letter to Jesse Sharkey, president of the Chicago Teachers Union, imploring teachers to return to the classroom while negotiations continued. The mayor and schools CEO emphasized concern for the health and well-being of students and said the strike was jeopardizing playoff prospects for several of the city’s top-ranked high school sports teams.

“What we’ve seen is that students and families have sacrificed a great deal that cannot be recovered,” Lightfoot and Jackson wrote. “Given where we are in negotiations, this hardship is unnecessary.”

The union declined the request to go back to the classroom.

“I don’t know if the mayor knows how labor negotiations work,” Sharkey told WMAQ. “We’re not going back to work without a legally binding agreement.”

Wednesday, teachers rallied outside city hall as Lightfoot delivered her first budget address. They shut down several downtown streets, tying morning rush-hour traffic in knots. Lightfoot announced an additional $163 million for Chicago Public Schools, but the amount will not satisfy teachers’ demands.

Some marginal signs of progress emerged. Michelle Gunderson, a teacher and trustee with the union, tweeted a photo of teachers gathered in a room with a document projected on a screen.

“We are reaching tentative agreements on many items,” Gunderson wrote Wednesday.

On Monday, Sen. Elizabeth Warren (D-Mass.), who is seeking the Democratic presidential nomination, showed up at a rally at Oscar DePriest Elementary to express her support for the strike, wearing a quilted jacket in red to match the striking teachers.

Marching downtown on Wednesday, teachers pledged to remain out as long as necessary to press the city to meet their demands.

“My kids have social and emotional issues and are screaming for help,” said Kenziesha Charleston, who teaches second grade at Murray Language Academy. The school has a social worker only one day a week. “I am trying to teach and figure out how to teach them to cope. I am only one person. We are tired.”

Jeanne Bakula, who teaches at Schubert Elementary School, said nearly every student comes from a low-income household and many rely on school meals.

“For many of these kids, this is the only meal they are getting,” Bakula said.

Her students have sometimes endured trauma, and they struggle to learn. The school system, she said, needs to provide students with more mental health support.

“It’s hard to teach and be a counselor at the same time,” Bakula said.

Teachers emphasized the work other school staff members perform.

Katherine Klinger, who teaches at John M. Palmer Elementary, lamented that her school has a nurse present just one day a week, leaving her nervous about students who need inhalers for asthma and rescue medication for allergies.

The strike posed hardships for parents, and their patience was fraying.

Fantasia Martin was waiting for a bus on Wednesday with her daughters Daliylah, 7, and Anastasia, 8. The girls are getting bored and antsy, their mother said.

“I hope the strike ends sooner, and they do what they need to do. It’s not benefiting the kids or parents,” Martin said. “School is their safe place, and it’s where they get a meal, too.”

Balingit reported from Washington.