ORLANDO, Florida — The city of Orlando has proceeded with a second test of Amazon's facial-recognition technology, it said Thursday.

Amazon's Rekognition software analyzes security camera video and attempts to identify the people in it by scanning faces and searching databases.

Privacy concerns have been raised by a coalition of groups, which include the American Civil Liberties Union, immigration advocacy groups and the Orange County Classroom Teachers Association, among others.

In a news release, the city of Orlando said the second pilot test of Rekognition started Thursday and would last nine months.

The city said no images from the public would be used in this portion of the test, only Orlando Police officers who have agreed to participate. In July, Chief John Mina said seven officers had volunteered.

Eight video streams from city-owned cameras are included: four at Orlando Police Department headquarters, plus three cameras in undisclosed public places in the city, and one more unnamed city facility.

During this portion of the test, the technology won't be used in an investigative capacity, the news release said.

Rekognition can identify up to 100 people in a single image, using a private repository of images, and can identify people in an image even when their faces aren't clearly visible, Amazon says.

The city's first test of the technology lasted six months and ended June 19. After this second test, the police department will decide on whether to continue to use the technology. Then the city will explore how to purchase it and develop a policy for how it will be used.