A US drone strike killed a leader of so-called Islamic State (IS) in Syria hours after the same MQ-9 Reaper drones were harassed by Russian military jets over the western part of the country, according to US officials.
Three Reapers had been flying overhead searching for the militant on Friday, a US defence department official said, when they were harassed for about two hours by Russian aircraft.
Shortly after this, the drones struck and killed Usamah al-Muhajir, who was riding a motorcycle in the Aleppo region, the official said.
The official said Mr al-Muhajir was in northwest Syria at the time of the strike, but that he usually operated in the east.
It was not immediately clear how the US military confirmed that the person killed was Mr al-Muhajir and no other details were provided.
In a statement released on Sunday, US Central Command said there were no indications that any civilians had been killed in the strike but that the military were assessing reports a civilian may have been injured.
Friday was the third day in a row that US officials complained that Russian fighter jets in the region had conducted unsafe and harassing flights around American drones.
Lieutenant General Alex Grynkewich, head of US Air Forces Central Command, said in a statement that during the Friday encounter, the Russian planes “flew 18 unprofessional close passes that caused the MQ-9s to react to avoid unsafe situations”.
The first friction occurred on Wednesday morning when Russian military aircraft “engaged in unsafe and unprofessional behaviour” as three American MQ-9 drones were conducting a mission against IS, the US military said.
On Thursday, the US military said Russian fighter aircraft flew “incredibly unsafe and unprofessionally” against both French and American aircraft over Syria.
Colonel Michael Andrews, Air Forces Central Command spokesman, said the Thursday incident lasted almost an hour and included close fly-bys by one SU-34 and one SU-35 and that they had deployed flares directly into the MQ-9.
US officials said the drones were unarmed in the earlier flights, but were carrying weapons on Friday, as they were hunting Mr al-Muhajir.
“We have made it clear that we remain committed to the defeat of Isis throughout the region,” General Erik Kurilla, commander of US Central Command, said in the statement.
Rear Admiral Oleg Gurinov, head of the Russian Reconciliation Centre for Syria, said this past week that the Russian and Syrian militaries had started a six-day joint training that would end on Monday.
Mr Gurinov added in comments carried by Syrian state media that Moscow was concerned about the flights of drones by the US-led coalition over northern Syria, calling them “systematic violations of protocols” designed to avoid clashes between the two militaries.
