Australian authorities have lost contact with a large air tanker fighting bush fires in alpine areas of the southeastern state of New South Wales, said officials from the New South Wales Rural Fire Service on Thursday.

"The NSW Rural Fire Service is investigating reports of a serious incident involving an aircraft in southern NSW this afternoon," the agency wrote on Twitter.

Fire crews have been battling blazes in the area amid extreme temperatures.

Al Jazeera's Andrew Thomas joins us live from Sydney for the latest updates.