Federal auto safety regulators have opened a probe into Cruise, which operates self-driving cars in San Francisco.
The National Highway Traffic Safety Administration says it's looking into whether the autonomous vehicles are safe enough for pedestrians.
It comes in response to two reports from the company, which is owned by General Motors, about incidents where pedestrians were injured by cars from the Cruise fleet.
It includes one instance where a pedestrian was first hit by a car driven by a human and then got run over by a Cruise car in San Francisco earlier this month. Cruise denied that it was to blame for that crash.
The other incident under investigation occurred on August 26 when a pedestrian allegedly stepped into a crosswalk in front of a Cruise car even though the light was green for the driverless car, according to Cruise. The pedestrian was hit by the car which was traveling between 1.4 miles per hour, Cruise said.
"Cruise communicates regularly with NHTSA and has consistently cooperated with each of NHTSA'S requests for information – whether associated with an investigation or not – and we plan to continue doing so," said Cruise spokesperson Hannah Lindow in an email to KTVU.
Cruise and Waymo, a competitor in the self-driving car business, both won approval to expand their services in San Francisco from state regulators in August.
But criticism of the companies has also grown as witnesses have posted numerous videos of autonomous vehicles blocking intersections and hindering the work of emergency responders.