Hyundai Motor’s Ulsan plant experienced production disruptions on Wednesday after workers at supplier Motras joined a general strike organized by the Korean Confederation of Trade Unions.

Parts shortages led to reduced operations at most production lines and the temporary halt of some lines from 1:30 p.m.

Motras, a Hyundai Mobis subsidiary, supplies electronic modules and employs around one-thousand-500 union members, who staged a four-hour walkout.

The strike stems from unresolved demands over job security and new contracts.

Meanwhile, only about 200 senior members of Hyundai Motor’s union participated in the strike, a relatively small turnout that limited its broader impact.

Workers at HD Hyundai Heavy Industries, which has been struggling with wage negotiations, also staged a four-hour strike, though no significant production issues were reported.