SYDNEY, Feb 21 (Reuters) - Airlines have been contacted by Australia's air traffic control agency warning them of reports of live fire off the country's east coast where a Chinese navy task group has been operating, the agency and Australian officials said.

A People's Liberation Army Navy frigate, cruiser and replenishment vessel last week entered Australia's maritime approaches, and travelled down Australia's east coast this week, monitored by the navies and air forces of Australia and New Zealand.

"The Civil Aviation Authority and Airservices Australia are aware of reports of live firing in international waters," air traffic control agency Airservices Australia said in a statement on Friday.

"As a precaution, we have advised airlines with flights planned in the area," it added.

Qantas QAN.AX and its low-cost arm Jetstar are monitoring the airspace and have temporarily adjusted some flights across the Tasman Sea between Australia and New Zealand.

Foreign Minister Penny Wong said the live fire involved the Chinese task group and it was an evolving situation.

"It is, as I understand it, operating in international waters," she said in an ABC television interview on Friday.

"We will be discussing this with the Chinese, and we already have at officials level, in relation to the notice given and the transparency, that has been provided in relation to these exercises, particularly the live fire exercises."

The Sydney Morning Herald reported China had notified Australian authorities on Friday they would hold an exercise off the coast of New South Wales state.

Defence Minister Richard Marles did not immediately respond to a request for comment.

(Reporting by Kirsty Needham, Byron Kaye and Alasdair Pal in Sydney; Editing by Jamie Freed)

((Kirsty.Needham@thomsonreuters.com;))