TEHRAN, Young Journalists Club (YJC) - Teachers have been flexing their political muscle in Republican-dominated states where education funding was cut in recent years.
Demonstrators were inspired by a nine-day strike that last month won West Virginia's teachers their first pay raise in four years. Teachers in Arizona held another rally in late March.
Organizers were predicting a turnout of 30,000 in Oklahoma City, where aerial television images showed a large crowd, with many in red shirts, gathered outside the state capitol.
"The message today I believe is about kids. It's about funding public education and really restoring the kind of support that all kids need in order to learn," Oklahoma state schools chief Joy Hofmeister told TV station KWTV.
Monday's walkouts shuttered some classrooms, with administrators unable to find enough substitutes to keep schools open. Other schools were already closed due to a scheduled holiday.
Some districts were facing days-long closures, as teachers vowed to continue until their demands were met.
Oklahoma City Public Schools announced its campuses would be shut through Tuesday. Hundreds of other school districts in the state also were closed, according to media reports.