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Thousands of Sacramento public school teachers are participating in a one-day strike Thursday, demanding lower class sizes and other school improvements they say the district promised but never delivered.

Educators and their supporters, including students, picketed outside C.K. McClatchy High School and held signs that read "Honor our Contract," "Keep Your Promises to Our Kids" and "Unfair Labor Practices Strike."

California Teachers Association President Eric Heins led teachers in chanting "enough is enough."

"Starting in West Virginia to Oklahoma to Arizona, all across the country teachers have been saying 'enough is enough,' " Heins said. "In L.A. they were saying 'enough is enough.' In Oakland they were saying 'enough is enough.' And now here in Sacramento they're standing up and they are saying ‘enough is enough.’ "

The Sacramento City Teachers Association, the union representing some 2,800 teachers, nurses and resource specialists, accuses the school district of backtracking on the terms of its 2017 agreement and engaging in unlawful labor practices. As part of that deal, the union claims the district committed to reducing class sizes and hiring more nurses and counselors with funds it saved from switching to a cheaper health plan, the Sacramento Bee reported.

“We don’t want to go on a strike, but that is our lawful way of getting the district to live up to its commitments,” SCTA President David Fisher wrote to the district last month.