UPDATE 1-Los Angeles schools disrupted for sixth day in teachers strike

Los Angeles's first teachers' strike in 30 years disrupted classes for a sixth school day on Tuesday, after overnight negotiations between the union and the second-largest U.S. school district produced no deal. Classes have been disrupted for some 500,000 students after 30,000 teachers walked off the job demanding the Los Angeles Unified School District (LAUSD) raise their pay, cut class sizes and the hire of more support staff such as nurses.

Hundreds of firefighters attending a conference in Los Angeles rallied downtown on Tuesday in support of the stoppage, joined by a marching band of striking music teachers, according to the union. The United Teachers Los Angeles union and Mayor Eric Garcetti, who does not have direct oversight of the schools but is acting as mediator, said on Monday that progress was being made in talks.

Negotiations continued for 21 hours through to 6:13 a.m. PT (1413 GMT) on Tuesday, with teams due to reconvene again about two hours later, Garcetti's office said in a statement. The union also has sought restrictions on the steady expansion of independently operated charter schools, arguing they divert resources from the bulk of the district's students.

Union supporters and district officials alike have credited the striking teachers with reawakening public, media and politicians to years of neglect in public school systems around the country. Sympathy for the strike has run high among Los Angeles parents, despite the disruption.

The district has said all of its 1,200-plus schools will be open again this week on a limited basis as long as the walkout continues, though attendance during the first five days of the strike dwindled to a fraction of normal levels. Schools were closed on Monday in observance of a national holiday commemorating slain civil rights leader Martin Luther King Jr.

There were a wave of teacher walkouts over salaries and school funding in several U.S. states last year, including West Virginia, Oklahoma and Arizona. The Los Angeles stoppage differs in that educators face a predominantly Democratic political establishment more sympathetic to their cause. LAUSD Superintendent Austin Beutner has framed the dispute in Los Angeles in terms of dollars and cents, saying there is too little money to meet teachers' demands in full without additional resources from the state.

Union President Alex Caputo-Pearl said the district's reserves had been understated, but also suggested additional state support may be needed to close a deal. (Reporting by Steve Gorman, writing by Jonathan Allen; Editing by Scott Malone and Susan Thomas)