Subway workers in Busan began an indefinite strike Wednesday at 5 a.m., but services during commuting hours will not be affected.

State-run Busan Metro is required to keep at least 1,010 workers on duty even during a strike, per public service corporation laws.

During daytime hours, the trains will run less frequently -- at 10- to 11-minute intervals, rather than the usual six minutes. 

The subway service is expected to operate at 70-75 percent capacity during non-commuting hours on weekdays and 68.9 percent on weekends and holidays, the corporation said.

Wage negotiations between labor and management at Busan Metro fell through Tuesday night.

In the negotiations, which began Tuesday at 3 p.m., the labor union backed away from its initial demand for an increase of 4.3 percent and asked for a 1.8 percent increase instead. The union also lowered the proposed number of new hires from 742 to 550. The management, however, insisted on a wage freeze and only 497 new employees.

Busan City said the city will secure alternative transportation services such as buses and taxes in case the strike is prolonged.

By Kim Arin (arin@heraldcorp.com)