A total of 1,610 school workers with non-guaranteed contracts across the country participated in a one-day strike Friday, disrupting lunch plans at 220 schools, according to the Seoul Metropolitan Office of Education.

The strike, led by an umbrella group of unions representing "non-regular" workers, was held in protest of their wage disparity with school workers with guaranteed contracts.

Korean companies usually sign permanent employment contracts with their "regular workers," and those with temporary contracts usually receive less in wages and benefits.

The effect of the short-term strike disrupted lunch plans for 220 of the 1,397 schools across the country, with 200 schools providing alternative lunches, such as store-bought bread and milk. Sixteen others did not provide lunch and altered their class schedules accordingly, while four instructed students to pack their own lunch from home.