A judge sentenced four black union members to death Friday for the murders of four black co-workers who refused to join a rail strike in 1987.

Four more black members of the South African Railway and Harbor Workers Union who pleaded guilty to the same killings were sentenced to prison terms of between eight and 12 years by Johannesburg Supreme Court Judge T.T. Spoelstra, who cited extenuating circumstances in their cases.According to evidence at the trial, many workers who refused to join a strike against the state rail company in March and April 1987 were kidnapped and beaten at the Johannesburg headquarters of the Congress of South African Trade Unions, a black labor federation.