WASHINGTON — The US-led anti-ISIS coalition conducted another airstrike Thursday against pro-regime forces in the de-confliction zone around the coalition base at At Tanf, Syria, two US officials told CNN.
The strike took place after three technical vehicles were observed crossing into the restricted area. Two of the vehicles were hit about 24 miles from the At Tanf base.
This is the third coalition strike in recent weeks against pro-regime forces near At Tanf and it comes days after a highly unusual move from the coalition where they permitted a pro-regime Syrian aircraft to conduct an airstrike inside a restricted zone in southern Syria where American forces were stationed.
Tuesday’s strike, which also took place near the US-manned At-Tanf Garrison on Syria’s southern border, was intended to protect Iranian-backed Shia militia fighters aligned with Syrian President Bashar al-Assad who had come under attack from anti-government forces.
The US does not support the militia group but approved the strike after a request from the Syrian government was relayed by the Russians through established communication channels.
But just hours later, the US-led coalition conducted its own airstrike against the pro-regime forces after they refused to leave the de-confliction zone.
Two US defense officials outlined the course of the events to CNN providing new details into what led to the coalition’s rare targeting of pro-regime forces.
Tuesday’s incident unfolded in several phases over a period of about six hours and began when a small number of Iranian-backed Shia militia fighters, located just inside the US restricted zone, came under ground attack from anti-government forces.
The militia fighters were just inside a 34-mile so-called de-confliction zone the US had set up weeks earlier.
The US had been trying to keep the zone clear of outsiders in order to protect American forces but a small number of militia fighters had remained in place until they were attacked on Tuesday.
When that attack happened, the US and Russians spoke on their established de-confliction communications channel. The Russians relayed a request from the Syrian government to conduct an airstrike to support their personnel on the ground and the US agreed, according to the US officials.
Some hours later, the US and Russia spoke again — this time the Russians passed along a request to evacuate wounded personnel from the restricted area using unarmed vehicles.
It wasn’t immediately clear how many wounded were evacuated.
But a short time later, the pro-regime forces begin bringing additional fighters and equipment into the area and when they refused to leave, the US carried out its own airstrike targeting the militia forces.
“Despite previous warnings, pro-regime forces entered the agreed-upon de-confliction zone with a tank, artillery, anti-aircraft weapons, armed technical vehicles and more than 60 soldiers posing a threat to coalition and partner forces based at the At Tanf Garrison,” a coalition statement said on Tuesday.
After several warnings over the de-confliction channel, the coalition destroyed “two artillery pieces, an anti-aircraft weapon, and damaged a tank.”
The airstrike was carried out by a US F/A-18 aircraft that dropped four bombs in total and killed an estimated 10 fighters in addition to the previously reported damaged and destroyed vehicles.
Last week, the coalition said that a relatively “small element” of pro-regime forces continued to hold their position inside the “de-confliction” zone surrounding the coalition training base.
Coalition spokesperson, Col. Ryan Dillon, told reporters last week that the pro-regime forces inside the zone represented an “armed and hostile presence” and “they pose a threat to us in that particular location.”