Railway workers’ work-to-rule protest entered its fourth day on Thursday, causing subway delays and inconveniences to citizens in the Seoul metropolitan area. 

According to the Korea Railroad Corporation, 14 out of 470 trains in the capital region saw delays of more than 20 minutes between 5 a.m. and 9 a.m. Thursday. 

Most of the delays affected Seoul subway Line No. 1, while the high-speed KTX and other regular trains are operating on schedule.

The union is demanding additional personnel and a two-point-five percent increase in the base salary.

The union also announced plans during a press conference Thursday to stage a general strike starting December 5.