United States forces in Syria shot down an armed drone affiliated with groups supporting Syrian President Bashar Assad's government overnight, the U.S.-led coalition said Tuesday.

"The armed pro-regime Shaheed-129 UAV was shot down by a U.S. F-15E Strike Eagle at approximately 12:30 a.m. after it displayed hostile intent and advanced on coalition forces," Operation Inherent Resolve said in a statement.

The incident came a day after the United States shot down a Syrian government fighter jet, ramping up tensions in the region and eliciting a threat from Russia to target U.S. aircraft. It happened near Al Tanf, where the United States has faced off against pro-Assad forces multiple times over recent week. The U.S. military is using the area near Syria’s border with Iraq and Jordan to train its local forces allied with the U.S.

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The Iranian-made drone was first intercepted by the F-15. It then continued to advance on coalition forces, at which point it was shot down, according to the statement.

"The coalition has made it clear to all parties publically and through the de-confliction line with Russian forces that the demonstrated hostile intent and actions of pro-regime forces toward Coalition and partner forces in Syria conducting legitimate counter-ISIS operations will not be tolerated," the statement said.

On Sunday, the U.S. military said it shot down a Syrian SU-22 plane in self-defense and after contacting Russian counterparts through the established de-confliction line. The Syrian aircraft was bombing U.S.-backed forces fighting the Islamic State in Iraq and Syria (ISIS) south of Tabqa.

Russia responded by saying its surface-to-air missile systems in Syria would track manned and unmanned aircraft from the U.S.-led anti-ISIS coalition as targets if they go west of the Euphrates River.

The coalition appeared to allude to Russia's threat in its statement on Tuesday.

"Given recent events, the coalition will not allow pro-regime aircraft to threaten or approach in close proximity to coalition and partnered forces," it said.

Al Tanf has been the site of three other incidents. On May 18, the United States conducted airstrikes on an Iranian-backed pro-Assad militia that it said came within the established de-confliction zone around the training base.

That was followed by another strike against an Iranian-backed pro-regime militia on June 6 when it came into the de-confliction zone with a tank, artillery, anti-aircraft weapons, armed technical vehicles and more than 60 soldiers.

Two days later, the United States shot down an armed pro-regime drone after it fired a munition that failed to detonate at U.S.-led forces. U.S. officials have not said who was operating the drone, but have said it was Iranian-made.

--This report was updated at 10:34 a.m.