CHICAGO (CBS) — As the Chicago Teachers Union and Chicago Public Schools leadership continue pointing fingers in public, and negotiations drag on behind closed doors, all signs point to the teachers strike stretching at least into the weekend.

While union officials said they have reached tentative agreements on 80 contract issues after Wednesday’s bargaining session, they said talks remain stalled on the major issues of salaries, class sizes, and staffing.

Teachers have been on strike since last Thursday, and CPS students have missed six days of classes during the work stoppage.

Both sides returned to the negotiating table Thursday morning at Malcolm X College, a day after teachers held a massive rally downtown while Mayor Lori Lightfoot was presenting her city budget address.

No major rallies were planned on Thursday, as teachers returned to picket lines outside of schools in the morning. CTU has said teachers later will canvass around local schools, and then gather Thursday afternoon for “nonviolent civil disobedience training” at union headquarters.

Meantime, CTU and support staff represented by SEIU Local 73 are planning a big rally on Saturday in Union Park, hosted by the Illinois Federation of Teachers. School support staff represented by SEIU also have been on strike since last Thursday.

“As the strike goes into its second week, it is time to show that Chicago is a Union Town and support the efforts of these courageous workers with solidarity,” the Illinois Federation of Teachers wrote in a Facebook event page for the rally.

The union and CPS leadership continue to blame each other for the slow progress of contract talks.

“Every day that goes by, there’s another cost to our young people, our students, and their families; and we’re just not seeing the kind of progress that we need to from CTU,” Mayor Lori Lightfoot said Thursday morning.

CTU President Jesse Sharkey, however, said the mayor must bring more resources to the table in order to reach a settlement.

“We’re trying to put together a puzzle in order to end this strike, but we don’t have enough pieces on the table in order to complete the puzzle. The mayor still has a handful of pieces in her pocket,” Sharkey said. “Until she takes the pieces of the puzzle out of her pocket and puts them on the table, we’re not going to solve the puzzle, we’re not going to complete the picture, and those pieces amount to resources.”

The mayor has repeatedly said CPS does not have any more money than it already has put on the table to meet the union’s demands for pay, class sizes, and staffing.