Two objects possibly related to the search for missing Malaysia Airlines flight MH370 have been sighted by satellite in the remote southern Indian Ocean, Australian officials said Thursday, calling it the "best lead we have".

Prime Minister Tony Abbott said the "new and credible information" had come to light nearly two weeks after the plane vanished en route from Kuala Lumpur to Beijing with 239 passengers and crew on board.

Thai radar picked up an "unknown aircraft" minutes after flight MH370 last transmitted its location but officials failed to report the findings earlier as the plane was not considered a threat, the air force said Wednesday.

The information emerged during checks of radar logs on Monday -- nine days after the Malaysia Airlines jet carrying 239 passengers and crew disappeared -- after a request from the Malaysian government, according to Air Marshal Monthon Suchookorn.

An Australian man killed in the Syrian conflict was a former soldier who went absent without leave several years ago, a senior official revealed Wednesday.

Reports said that Caner Temel, 22, was killed on the frontline in January after traveling to Syria to fight in the civil war, joining up with the Islamic State of Iraq and the Levant (ISIL) radical jihadist group.

Australia on Wednesday said it will impose targeted financial sanctions and travel bans against officials involved in the annexing of Crimea, rallying behind allies the United States and the European Union.

While none of the 12 Russian and Ukrainians in the firing line was named, Foreign Minister Julie Bishop said they were "individuals who have been instrumental in the Russian threat to the sovereignty and territorial integrity of Ukraine".

Australia announced plans Thursday for a fleet of giant high-tech unmanned drones to help patrol the nation's borders, monitoring energy infrastructure and attempts to enter the country illegally.

Prime Minister Tony Abbott said the Triton Unmanned Aerial Vehicles, which can remain airborne for 33 hours, would be based in the southern city of Adelaide.

The only known specimen of the first official banknote issued in Australia, uncovered in Scotland, is expected to fetch at least Aus$250,000 (U.S.$224,000) at an auction in Sydney this month, officials said Wednesday.

The ten shilling note, issued on the order of New South Wales governor Lachlan Macquarie in 1817 by the Bank of New South Wales (now called Westpac) on the day it opened, is expected to attract bids from collectors around the world.

Australia's government rejected a request from Qantas Airways for a $2.7 billion unsecured loan to help the national carrier return to profitability, deciding instead to abolish foreign ownership restrictions, the prime minister said Wednesday.

In the wake of Monday's decision to allow greater foreign ownership of Qantas, Prime Minister Tony Abbott said his ministers had acted on expert advice from accounting firm PricewaterhouseCoopers to decide that Qantas did not need the line of credit.

Australia has offered temporary refuge to visiting Ukrainians due to soon return to their country, which is in turmoil.

Foreign Minister Julie Bishop told Parliament on Wednesday that Ukrainian nationals could apply for visa extensions to stay temporarily in Australia "while their nation is under threat."

An Australian warship has rescued 13 Iranians shipwrecked off Pakistan on its way to the Middle East to join an international force conducting counter-terrorist and anti-piracy operations, officials said Wednesday.

HMAS Darwin came across the men, some elderly, on Saturday in calm seas after their boat was reportedly struck by an unknown vessel and sank. They claimed to have been adrift for five days in international waters.

Australia will suffer more days of extreme heat and a longer bushfire season as greenhouse gases force temperatures to continue rising, a new report warned Tuesday.

The joint study by the Commonwealth Scientific and Industrial Research Organisation and the Bureau of Meteorology said temperatures across Australia were, on average, almost 1.0 degree Celsius (1.8 degrees Fahrenheit) warmer than a century ago.