WASHINGTON, Oct 9 (Reuters) - The National Highway Traffic Safety Administration said on Thursday that it is opening an investigation into 2.88 million Tesla vehicles equipped with its Full Self-Driving system over traffic-safety violations.

Tesla shares fell 2% in morning trading.

The auto safety agency said FSD -- an assistance system that requires drivers to pay attention and intervene if needed -- has "induced vehicle behavior that violated traffic safety laws".

The agency said it has reports of Tesla vehicles driving through red traffic lights and driving against the proper direction of travel during a lane change, while using the system.