Videos show driverless Teslas braking hard without warning - and on wrong side of the road

Regulators are looking into suspected problems with Elon Musk's self-driving "robotaxis" after videos showed a few braking suddenly and driving on the wrong side of the road.

The tests began on Sunday in Austin, Texas, and it's the first time Tesla cars without a human driver have carried paying passengers. Musk sees the concept as a major part of the company's financial future and envisages thousands of the cars operating across the US.

However, the National Highway Traffic Safety Administration said on Tuesday it was looking into the apparent errors. "NHTSA is aware of the referenced incidents and is in contact with the manufacturer to gather additional information," the agency said.

One video shows a Tesla in a left turn-only lane going straight through an intersection, with the steering wheel shaking erratically, before it briefly veers in the wrong lane. Another clip shows a robotaxi brake hard several times in the middle of the road, apparently responding to the flashing lights of parked police cars.

Tesla has so far not responded to the videos. Ten robotaxis are reportedly part of the Austin test - and in other social media videos they appear to operate as intended and get the thumbs up from reviewers.

Tesla shares jumped 8% on Monday as the programme appeared to get off to a good start, but on Tuesday they dropped back nearly 3%. The cars are initially overseen by a human "safety monitor" in the front seat - but it's unclear if they've had to intervene in any incidents.

Read more from Sky News:Minecraft users targeted by criminals posing as codersDoctors using unapproved AI to record patient meetings Federal regulators also last year launched an investigation into how some privately owned Teslas reacted in low-visibility scenarios following several accidents, including one that was fatal. Elon Musk's vision is to rapidly roll out the robotaxis, but apart from safety concerns he faces competition from current market leader Waymo.

The company is a subsidiary of Google owner Alphabet and already offers self-driving taxis - mostly without any human "safety monitor" - in Austin, Los Angeles, Atlanta, San Francisco and Phoenix..