A Seoul court on Wednesday ordered four leaders of the state rail company's labor union, accused of spearheading an "illegal" strike, to remain in prison. The leaders of the union of state-run Korea Railroad Corp. (KORAIL), including its head Kim Myung-hwan, have been detained since Jan. 17 on suspicion of playing leading roles in the strike that disrupted the national rail system for more than three weeks, the longest such strike ever. The government claims that the strike has caused huge financial loss.