DENVER (Reuters) - Denver public school teachers walked off the job on Monday to demand higher and more predictable earnings, disrupting classes for some 92,000 students in the latest of a wave of strikes by U.S. educators over the past year.

The walkout comes after a six-day strike by Los Angeles school teachers ended last month in a deal to reduce class sizes and raise salaries by 6 percent, and follows statewide work stoppages last year in West Virginia, Kentucky, Oklahoma and Arizona.

Weekend negotiations between Denver’s 5,650-member teachers’ union and the school district broke down over a pay scheme that the union says has sacrificed dependable cost-of-living wage hikes in lieu of limited bonuses offered for teaching in high-poverty areas and challenging classrooms.

The two sides said they planned to return to the bargaining table on Tuesday.

In the meantime, all 207 schools in Colorado’s largest school district remained open, staffed by substitute teachers and administration personnel.

Hundreds of teachers weathered sub-freezing temperatures in Denver as they marched through snowy streets chanting and holding protest signs. Striking educators and supporters later rallied at the state Capitol.

“There is no data to support that bonuses keep teachers at higher-need schools,” said Gerardo Munoz, 43, a social studies teacher. His wife, Claudia Munoz, 39, added, “I worked at one (higher-need school) and could have stayed, but I was overworked and underpaid.”

BONUS PAY DISPUTE

Denver Public Schools Superintendent Susana Cordova said the district had proposed a pay increase of nearly 11 percent next year, which would boost the average salary for teachers to $61,000, from $55,000.

But Robert Gould, lead negotiator for the Denver Classroom Teachers Association bargaining team, said the district was inflating the true value of its latest offer.

The dispute has centered on an incentive pay package containing bonuses for educators to teach in hard-to-staff subjects such as math and science, or schools in low-income areas, or who teach in one of a handful of “distinguished” schools.

Administrators say the so-called ProComp incentive system, paid for with special funding approved by local voters in 2003, is needed to attract and retain quality educators.

But union leaders counter that a focus on bonuses has led to higher teacher turnover. They are seeking a more traditional compensation package with a higher base salary and built-in increases for teachers who further their education, training and experience.

Union and district negotiators deadlocked during a bargaining session on Saturday night, setting the stage for the strike, the first in the city since a five-day walkout in 1994.

“We’re hoping they come to the table tomorrow ready to listen so we can get back to work, because our teachers want to be in the classrooms with their kids,” Gould told reporters.