Unionized workers at Hyundai Motor Co., South Korea's top automaker, walked off the job for four hours on Tuesday demanding a pay raise and better working conditions. 
Last week, a majority of the automaker's some 48,000 unionized workers voted for a strike as their talks with the company's management over a wage increase and other issues were ruptured. 
The workers will also put down their tools for four hours a day on Wednesday, Thursday and Friday. Hyundai Motor estimates some 40 billion won (US$35 million) a day in production losses due to the partial strike. 
Also, employees at Hyundai Heavy Industries Co., a major shipyard in the country, also staged a strike for four hours on Tuesday, demanding that the company's tough restructuring move, including a cut in workforce, be scrapped. 
Their partial walkout will also take place on Wednesday and Friday.