SYDNEY (Reuters) - Australia said it was concerned that one in ten cybersecurity incidents last year involved critical infrastructure, with state-sponsored actors targeting the country's government, infrastructure and businesses using evolving tradecraft.

The Australian Signals Directorate said in a report on Wednesday over 11% of cyber security incidents last year related to critical infrastructure, including electricity, gas, water, education and transport services.

Of these, a quarter were phishing incidents, 21% were exploitation of a public-facing interface, and 15% brute-force activities.

"We are worryingly seeing an increased focus by both cyber criminals and state actors on our critical infrastructure," Defence Minister Richard Marles said in a radio interview with the Australian Broadcasting Corporation.

Australia had joined international partners in attributing cyber incidents over the year to China, Russia and Iran, he added.

China was evolving cyber techniques, with the choice of targets and behaviour "consistent with pre-positioning for disruptive effects rather than traditional cyber espionage operations", the report said.

Beijing has repeatedly denied claims by the U.S. and Australian governments that it has used hackers to break into foreign computer systems.

(Reporting by Kirsty Needham; Editing by Sonali Paul)