Australia sanctions Russian billionaires with mining industry links.

SYDNEY, March 18 (Reuters) - Australia imposed sanctions on Friday on two Russian oligarchs with links to its mining industry, one of them a billionaire with an investment connection to Rio Tinto's Gladstone alumina refinery joint venture.

Foreign Minister Marise Payne said Australia was working in close cooperation with international partners to increase sanctions pressure on oligarchs close to Russian President Vladimir Putin over the invasion of Ukraine.