WASHINGTON, May 29 (Reuters) - Amazon.com's ( AMZN )

self-driving unit Zoox issued a second software update to

improve how its vehicles track nearby pedestrians and prevent

movement when someone is close, following a crash in San

Francisco earlier this month, the company said Thursday.

The recall covers 270 vehicles equipped with its

self-driving software, Zoox said in a report with the National

Highway Traffic Safety Administration on Thursday.

On May 8, a person on an electric scooter was turning at low

speed at a San Francisco intersection and struck an unoccupied

Zoox robotaxi, the company said.

The rider sustained minor injuries and fell next to the

vehicle, which then began to move and then stopped without

making further contact, the company said. The incident prompted

Zoox to temporarily suspend on-road operations to conduct a

review.

Zoox said the software update will address an issue

involving pedestrians and its self-driving vehicles that are

stopped or moving very slowly or about to resume travel. Under

certain rare scenarios, the Zoox vehicle may resume travel

without continuing to detect the presence of the nearby person,

the company said.

Zoox paused all driverless vehicle operations after the

incident and then implemented a software update and conducted

simulation and testing, it said, adding it resumed operations

last week.

All of the vehicles are owned by the company and are not

yet available for sale to the general public.

Zoox has been testing self-driving vehicles on public

roads since 2023 in California and Nevada and last year expanded

testing to Florida and Texas. The test fleet now operates in the

Bay Area, including San Francisco, as well as Los Angeles, Las

Vegas, Seattle, Austin, and Miami.

Earlier this month, Zoox issued a software recall for 270

driverless vehicles after an unoccupied robotaxi was involved in

an April 8 crash with a passenger car in Las Vegas.

In April, NHTSA closed a probe into 258 Zoox vehicles over a

braking issue after the company issued a recall to update its

software.