Australia said Thursday it had lifted a suspension of its airstrikes against Islamic State targets in Syria that was imposed amid tensions with Russia after a U.S. fighter jet shot down a Syrian warplane this week.

The Defense Department revealed on Tuesday that the six Australian F/A-18F Super Hornets based in the United Arab Emirates had been suspended from Syrian operations after Russia warned the U.S.-led coalition not to fly over Syrian army positions west of the Euphrates River.

"This was a precautionary measure to allow the coalition to assess the operational risk," a department statement said on Thursday. "The suspension has since been lifted."

The department has not specified how long the suspension lasted. It did not say if Australian airstrikes had resumed or when or if they would.

Australian Defense Force Chief Mark Binskin said on Wednesday the operations were halted while the Australians examined what was happening in what he had described as a "complex piece of airspace" over Syria.

Defense Minister Marise Payne said on Wednesday Australian "force protection is uppermost in our minds" in deciding when to resume missions over Syria.

Binskin said the jet fighters had been occupied recently supporting Iraqi security forces in retaking the city of Mosul, so the suspension had little effect on their operations.

The U.S. on Sunday shot down a Syrian jet for the first time during the conflict near the city of Raqqa after it dropped bombs near the U.S.-allied Syrian Democratic Forces, which are battling IS. Russia condemned the U.S. action and in retaliation suspended a hotline intended to prevent such incidents.