A misdirected airstrike by the U.S.-led coalition earlier this week killed 18 fighters allied with them in battling the Islamic State in northern Syria, the U.S. military said Thursday.
The Kurdish-dominated Syrian Democratic Forces requested Tuesday’s strike to take out ISIS militants at a fighting position south of Tabqa, a town close to the terrorist group’s self-declared capital of Raqqa. But they gave coalition aircraft incorrect coordinates.
“The coalition’s deepest condolences go out to the members of the SDF and their families. The coalition is in close contact with our SDF partners, who have expressed a strong desire to remain focused on the fight against ISIS despite this tragic incident,” U.S. Central Command said in a statement.
The coalition is investigating the incident and “will implement appropriate safeguards” to prevent it from happening again, according to Central Command, which oversees U.S. operations in the Middle East.
This week’s strike is the worst confirmed friendly-fire incident since the U.S. began operations against ISIS in 2014. It was not immediately clear which country had provided the air power for the strike.
There have been at least 37 reported incidents of coalition friendly-fire strikes in Iraq and Syria since 2014, according to the Britain-based monitoring group Airwars. Of those, the coalition has confirmed four, including a strike last September that killed at least 15 friendly Syrian forces The confirmed strikes also include a December 2015 strike in Fallujah that killed at least nine Iraqi soldiers and a strike near Mosul last October that killed 18 friendly Sunni Muslim tribal militia members.
[READ MORE: U.S. acknowledges a ‘fair chance’ its airstrike killed scores of civilians in Mosul]
In the last month, the U.S. military has opened three investigations into whether it was responsible for the deaths of nearly 300 Syrian and Iraqi civilians in three separate airstrikes.
In the worst incident, the top U.S. commander in Iraq acknowledged “there is a fair chance” that U.S.-led airstrikes had been responsible for the deaths of civilians in Mosul, where local reports say more than 200 people were killed. The Pentagon also opened a formal investigation into an airstrike in northern Syria on March 16 that local reports say struck a mosque that was crowded for evening prayers, killing more than 40 people.
[READ MORE: Pentagon denies airstrike hit mosque in Syria, says target was al Qaida militants]
The friendly fire incident came as anti-ISIS fighters, backed by coalition air power and U.S. special forces, have been preparing to mount an offensive against Raqqa.
The Syrian Democratic Forces have continued to advance toward the city, clearing an area “where the enemy remains completely isolated,” Air Force Col. John Dorrian told reporters via teleconference at the Pentagon on Wednesday.
“They are now nearing positions to enable their assault to liberate the city,” he said.
Vera Bergengruen: 202-383-6036, @verambergen