Rome, March 13 - A sinkhole opened up overnight on the Gianicolense ring road in Rome and two parked cars fell into it. One car was almost completely engulfed ed by the three-metre wide hole while the other one was only partially swallowed up, local sources said. No one was hurt. The number of potholes in the capital has become a hot-button issue and Mayor Virginia Raggi has announced a 'Marshall Plan' to repair them. Many fresh potholes have appeared after recent rain and snow.