Reports of serious crimes rose 6% in 1986, the biggest increase in seven years, the FBI said. It said that incidences of eight major offenses rose 6%, and that all types of crime showed upswings in all regions of the country. Violent crimes increased by 12%, led by a 9% rise in murder and robbery; property crimes rose 6%. The FBI acknowledged that its figures differ from those of the Justice Department's Bureau of Justice Statistics, which counts both reported and unreported crimes. Last month, the statistics bureau estimated that the crime rate in 1986 was basically unchanged, but it noted that a larger proportion of crimes was being reported.