Russian aircraft harassed American drones taking part in operations against the Islamic State jihadist group in Syria on Thursday for the second time in 24 hours, a US commander said.
Moscow's "military aircraft engaged in unsafe and unprofessional behavior Thursday, 9:30 am local time, while interacting with US MQ-9 drones," Air Force Lieutenant General Alexus Grynkewich said in a statement.
The planes "dropped flares in front of the drones and flew dangerously close, endangering the safety of all aircraft involved," he said.
The previous day, Grynkewich said Russian jets also dropped flares in front of US MQ-9s, while one pilot turned on their plane's afterburner in front of a drone.
Earlier this year, the United States said a Russian jet clipped the propeller of a drone operating over the Black Sea, causing it to crash. Moscow denied it was responsible.
This came only days after Israel carried out air strikes in Syria near the government-held city of Homs, and the Israeli army later said it struck an anti-aircraft battery after rocket fire.
A war monitor said the Homs-area strikes killed a member of Iran's Islamic Revolutionary Guard Corps.
During more than a decade of war in Syria, Israel has launched hundreds of air raids on Syrian territory, primarily targeting Iran-backed forces and Lebanese Hezbollah fighters as well as Syrian army positions.
"The Israeli enemy carried out air strikes coming from the northeast of Beirut, targeting some points in the vicinity of the city of Homs," which is about 20 kilometres (12 miles) from Lebanon, Syrian state-run news agency SANA said, quoting a military source.
SANA reported that Syrian air defences intercepted some missiles, and that there had been some "material" losses.
In a brief statement early Sunday that did not mention the air strikes, Israel's army said a Syrian anti-aircraft rocket "appears to have exploded in the air over Israeli territory".
Several hours later the military said it had targeted "an anti-aircraft battery in Syria, as a response to the launch of an anti-aircraft rocket from Syria into Israeli territory".
It added that Israeli jets had also "struck additional targets in the area", and that no injuries were reported from the Syrian missile.
Israeli media showed pictures purportedly from a piece of the missile about 1.5 metres (yards) in length which landed in Rahat, southern Israel.
The Syrian Observatory for Human Rights war monitor said the strikes targeted "Hezbollah sites and ammunition depots" on the northeastern outskirts of Homs, killing one member of Iran's Islamic Revolutionary Guard Corps (IRGC) and wounding four others.
- Iran 'advisers' -
Iran has long backed Syrian President Bashar al-Assad's government in the country's years-long civil war, but says it has no troops in Syria, only IRGC military advisers.
Israeli strikes in Syria killed two Revolutionary Guards in late March.
Along with Hezbollah, Assad is backed by Russian forces and has clawed back much of the ground lost early in Syria's conflict which erupted in 2011 when the regime brutally repressed pro-democracy protests.
Israel's latest strikes also targeted an air defence base in Qadmus, in Tartus province northwest of Homs, said the Observatory, which has a wide network of sources inside Syria.
Israel rarely comments on the strikes it carries out on Syria, but it has repeatedly said it will not allow its arch foe Iran to expand its footprint there.
On June 14, Israel carried out air strikes near Damascus wounding a soldier, according to SANA.
The Observatory, based in Britain, said at the time that the strikes had targeted arms depots belonging to pro-Iran fighters.