Since testing of self-driving cars on California’s public roads began in September 2014, four accidents have been reported.

Two of the accidents occurred while the vehicle was being piloted by a human while the other two happened while the vehicle was driving itself. In both the self-driving cases, the cars were travelling 10 mph or less.

Three of the incidents involved Google’s self-driving Lexus SUVs while the other vehicle belonged to auto supplier Delphi Automotive. In all four cases, the companies claim that their vehicles were not at fault. The California Department of Motor Vehicles confirmed the four accidents, but would not reveal any details.

A statement issued by Google says that its cars have been involved in “a handful of minor fender-benders, light damage, no injuries, so far caused by human error and inattention.” The tech giant says that this should be expected, given that its self-driving cars have travelled about 140,000 miles cumulatively.

In total, seven companies are licensed to test self-driving vehicles in California, with the fleet totalling 48 vehicles. Regulators in the other States that allow the testing of self-driving cars, which are Nevada, Michigan and Florida, say they are not aware of any self-driving car accidents.

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