Pro-Assad militia threatens to attack US positions in Syria

An Iranian-backed militia in Syria issued a stark warning to US forces on Wednesday, threatening to attack US positions if Washington crossed "red lines".

The statement from a pro-Assad alliance was circulated by a military news unit run by Lebanon's Hizballah and issued in the name of the "commander of the operations room of the forces allied to Syria," Reuters reported.

"America knows well that the blood of the sons of Syria, the Syrian Arab Army, and its allies is not cheap, and the capacity to strike their positions in Syria, and their surroundings, is available when circumstances will it," it said.

The silence of the "allies of Syria" was not a sign of weakness, but "an exercise in self-restraint," it added.

"This will not last if America goes further, and crosses the red lines," it said

It was not immediately clear if Assad-ally Russia was a signatory to the statement, which said that such attacks could be carried out with "missiles and military systems" due to the "deployment of American forces in the region."

The threat is a marked escalation in tensions between the US and Iran-backed forces for control of Syria's southeastern Badia region near the border with Iraq.

Hezbollah's Al-Manar TV on Wednesday aired footage from an Iranian drone tracking a US plane over southeast Syria.

Tensions between Tehran and Washington have heightened following the Arab-Islamic-US summit in Saudi Arabia last month, where US President Donald Trump singled out Iran as a "state sponsor of terrorism."

On Tuesday, the US launched airstrikes against Iranian-backed fighters who it said posed a threat to its forces, the second such attack in three weeks.

Last week, the US military dropped more than 90,000 leaflets to warn an Iranian-backed militia not to interfere in the coalition's anti-IS operations.

"We have increased our presence and our footprint and prepared for any threat that is presented by the pro-regime forces," US Army Colonel Ryan Dillon said at the time, referring to Iran-backed forces supporting Syrian regime president Bashar al-Assad.