US Navy F/A-18E Super Hornets flying a combat patrol over Afghanistan in 2008. The aircraft in the background is deploying infrared flares. Staff Sgt. Aaron Allmon, US Air Force

An F/A-18E Super Hornet fighter jet from the US-led coalition battling ISIS in Syria downed a Syrian SU-22 fighter over the countryside south of Raqqa on Sunday afternoon local time, according to a coalition press release.

On Sunday late afternoon, pro-Syrian government forces attacked the town of Ja'Din, south of Tabqah and west of Raqqa, ISIS' self-declared capital, the release said.

Ja'Din was held by coalition-backed Syrian Democratic Forces, and the Syrian strikes wounded some SDF fighters. Coalition aircraft stopped the initial strike through a show of force.

Coalition officials then contacted their Russian counterparts via a "de-confliction line" to stop the firing. But about two hours after the first strike by pro-Syrian government forces, a Syrian SU-22 fighter dropped several bombs near SDF fighters south of Tabqah.

"In accordance with rules of engagement and in collective self-defense of Coalition partnered forces," the release said, the SU-22 "was immediately shot down by a U.S. F/A-18E Super Hornet."

In a statement released on Syrian state television, the Syrian army said the US-led coalition shot down a Syrian army jet during a combat mission against ISIS fighters south of Raqqa.

The army's statement said the plane crashed and the pilot was missing.

The US-led coalition and its local partners have come into conflict with pro-Syrian government forces and their allies several times in recent weeks, as both sides jockey to assume control of territory given up by ISIS as the terrorist group loses strength in Syria.

All those earlier clashes came in the area around al Tanf, in southeast Syria near the country's borders with Iraq and Jordan. US special operations forces are on the ground near al Tanf to train local partner forces. (The US also reportedly stationed long-range rockets near al Tanf earlier this month.)

The area is seen as strategically valuable by the Syrian government and its Iranian backers, as well as by the US-led coalition and its local partners fighting ISIS. Russia has also reportedly launched strikes against militias opposed to the Syrian government in the al Tanf area.

As after those incidents, the US-led coalition said in a release Sunday:

"The Coalition does not seek to fight Syrian regime, Russian, or pro-regime forces partnered with them, but will not hesitate to defend Coalition or partner forces from any threat ... 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 al Tanf border crossing sits across the border from Iraq's al Waleed border crossing, which Iraqi government forces recently recaptured from ISIS militants.

A US fighter near a military vehicle north of Raqqa city, Syria, on November 6. Reuters/Rodi Said

Syrian government forces and allied militias reported meeting up with Iraqi forces near al Waleed in what Syrian officials called "the sign of the cooperation between the brotherly Iraqi and Syrian military leadership to secure the shared borders."

US officials said the meeting point was northeast of al Tanf and the Iraqi recapture of al-Waleed had "no bearing on Coalition partner training operations at At Tanf."

Iran has also fired on ISIS fighters in northern Syria in recent hours.

Iran's Revolutionary Guards Corps forces fired several surface-to-surface, medium-range missiles from western Iran at ISIS bases around Deir ez-Zur in northeast Syria.

The semiofficial Iranian news agency Tasnim said the IGRC was targeting ISIS because it held the group responsible for attacks in Tehran earlier this month that saw five ISIS-linked fighters storm the Iranian parliament building and a shrine to Ayatollah Ruhollah Khomeini. The attacks left 18 people dead and wounded more than 50.

"The spilling of any pure blood will not go unanswered," the IRGC said in a statement, according to Tasnim.