ARIZONA (AFP, Reuters) - Two escaped llamas led authorities in the United States on a long chase on Thursday as audiences nationwide were captivated by live video of their escapades filmed from television news helicopters.

The duo, one white and the other black, had the eyes of the world on them as American media transmitted live footage from the air of them darting across busy roads and parking lots in in Phoenix their brazen - and for a while successful - attempts at evading capture.

The llama drama began at lunchtime when a large white llama and a slightly smaller black companion were spotted roaming the north-western suburb of Sun City.

They were pursued by deputies from the Maricopa County Sheriff's Office and members of the public, often leading them to run in circles, and skipping away from capture at the last moment.

Twitter lit up after their heroics, with #whitellama, #llamas, #llamasontheloose and #teamllama all trending. There have been more than 220,000 Tweets on the mammals on Thursday alone, the social media service said.

After a chase lasting almost an hour, the pair became separated and the black llama was caught. Its boisterous white counterpart was eventually lassoed by a man from the back of a pickup truck.

Police said the pair escaped from a mobile petting zoo while it was visiting an assisted living centre as a form of animal therapy, and that they had been returned to their owners.

The Maricopa County Sheriff's Office said no criminal charges would be filed.