A 33-year-old Nigerian man suffered a broken collar-bone and other injuries after being attacked by four unknown youthful assailants, police in the western German city of Kaiserlautern said Friday, according to DPA. There was no apparent motive for the attack, which occurred in the early hours of Wednesday morning, police said. According to the victim, the assailants were aged 18 to 20 years. In recent months there have been repeated attacks on dark-skinned foreigners in Germany, with the formerly communist east gaining a reputation for racist assaults. In August, eight Indians suffered injury after being attacked by youths at a town fair in Muegeln in the eastern state of Saxony.