A judge who investigated Sicilian Mafia activities for a decade was ambushed and slain by at least six gunmen Friday while he was driving to work. Police blamed the Mafia.

Judge Rosario Livantino was driving without police escort.Court sources reported the shooting came hours before Livantino was to decide police surveillance for a number of Mafia suspects in the nearby towns of Porto Empedocle and Palma Di Montechiaro.

Police reported the gunmen blocked the car of the 38-year-old magistrate along the Canicatti-Agrigento state road. Police said Livantino managed to get out of his riddled car but was shot repeatedly by the gunmen. His body was left on the edge of the road.In other news . . . SHOWERS FELL in Kansas and Oklahoma Friday, and temperatures dipped into the 40s in the Northeast. . . . BORIS YELTSIN, the president of the Russian Federation and a key figure in the Soviet Union's mounting political and economic crisis, was involved in a car crash Friday, but an aide said he not hurt. . . . A TYPHOON flinging winds up to 72 mph dumped up to 14 inches of rain on central Vietnam, killing at least seven people. . . . A SERIES OF highway accidents involving two passenger buses and a van killed at least 33 people and injured 53 others in chain-reaction collisions on a rain-slick road in Indonesia.