U.S. auto safety regulators said on Thursday they are investigating a number of Tesla crashes, with possible links to its advanced driver assistance systems. Tesla's Autopilot allows drivers to keep their hands off the wheel for extended periods.Regulators said Thursday they've opened 30 investigations involving 10 deaths, in crashes since 2016. The National Highway Traffic Safety Administration released the list of incidents under review by its Special Crash Investigations programs.It had not previously released to Reuters a full accounting of their Tesla probes. It ruled out Tesla's Autopilot in three, and published reports on two of the crashes. Tesla did not immediately respond for comment. The National Transportation Safety Board said Autopilot was operating in at least three Tesla vehicles involved in fatal U.S. crashes since 2016. The NTSB has previously criticised Tesla's lack of system safeguards for Autopilot. The issue received renewed attention after a Texas crash in April in which two people died, and in which police believed no one was behind the wheel.The NTSB said in May, testing suggested the vehicle's automated steering system was 'not available' on the road where the accident happened. On Wednesday, the Senate Commerce Committee voted against moving ahead with regulations, that would speed the adoption of self-driving cars. Chair Maria Cantwell cited Tesla's crashes as a reason.