Sixteen migrant workers who donated blood for money were then robbed by the traders who had illegally bought it. Yesterday's Beijing Morning Post said the robbery happened last month when the migrants met the blood traders near the city's Chongwenmen subway station and were offered cash for blood. Each received 300 yuan for giving blood. But the traders took them to a secluded spot in Babaoshan and demanded a 50 yuan 'organising fee' from each migrant. The traders - identified as Jiang Qinglong, Zhou Bai'an and Zhang Guogui, all unemployed - robbed the migrants of their money. At least one migrant was severely beaten after resisting. The gang was arrested on Tuesday by Beijing railway police and had confessed to the crimes, the paper said. A law was passed in October last year banning the buying and selling of blood in the hope that it would help curb the contamination of blood supplies and check the spread of Aids. However, the report indicated the trade had not stopped and migrant workers, often discriminated against in cities, still fell victim to traders.