WASHINGTON 

The US carried out more retaliatory strikes against Iran-backed fighters in northeast Syria after American forces stationed in the area came under rocket fire that injured three troops.

US forces struck using AH-64 Apache attack helicopters, AC-130 gunships, and M777 artillery pieces, Central Command said in a statement. Four enemy combatants were killed and seven rocket launchers were destroyed, it added.

"We will respond appropriately and proportionally to attacks on our servicemembers," Central Command Commander Michael Kurilla said in a statement. "No group will strike at our troops with impunity. We will take all necessary measures to defend our people."

The attacks are the latest after US forces stationed at the Conoco outpost and Mission Support Site Green Village came under rocket fire Wednesday. The US launched retaliatory strikes using helicopters in the immediate aftermath, claiming they killed several Iran-backed militants believed to be responsible for the rocket attacks.

Earlier Wednesday, the US launched airstrikes in Syria targeting ammunition depots and logistics supply bunkers used by groups affiliated with Iran’s Islamic Revolutionary Guard Corps.

The airstrikes were ordered by President Joe Biden in retaliation for a series of attacks Aug. 15 at US military facilities in Syria.

The US and its enemies in Syria have been trading attacks for the better part of two weeks with neither side backing down.