A Russian troop deployment in Syria near the Lebanese border this week caused friction with Iran-backed forces including Hezbollah which objected to the uncoordinated move, two non-Syrian officials in the regional alliance backing Damascus said.
The situation was resolved on Tuesday when Syrian army soldiers took over three positions where the Russians had deployed near the town of Qusair in the Homs region on Monday, one of the officials, a military commander, told Reuters on condition of anonymity.
It appeared to be a rare case of Russia acting out of sync with President Bashar al-Assad's Iran-backed allies in the war. Iranian and Russian support has been critical to Assad's war effort.
"It was an uncoordinated step," said the commander. "Now it is resolved. We rejected the step. The Syrian army – Division 11 – is deploying at the border," said the commander, adding Hezbollah fighters were still located in the area.
There was no comment from the Russian military about the incident. Russia has faced calls from Israel to rein in Iran in Syria, where Israel has mounted numerous attacks against Hezbollah and other targets it has described as Iran-backed.
"Perhaps it was to assure the Israelis," said the commander, adding that the move could not be justified as part of the fight against the Nusra Front or Islamic State because Hezbollah and the Syrian army had defeated them at the Lebanese-Syrian border.
The second official said the "resistance axis" – a reference to Iran and its allies – was "studying the situation" after the uncoordinated Russian move.
Russia and Iran-backed forces such as Hezbollah have worked together against the insurgency. Hezbollah deployed to Syria in 2012. The Russian air force arrived in 2015 in support of Assad.
But their different agendas in Syria have become more apparent of late as Israel presses Russia to make sure Iran and its allies do not entrench their military sway in the country.
Israel wants Iranian and Iran-backed forces kept away from its border and, more broadly, removed from Syria entirely.
Last month, Israel said Iran's Revolutionary Guards launched a missile salvo from Syria into the Israeli-occupied Golan Heights. Hezbollah leader Sayyed Hassan Nasrallah said it marked a "new phase" of the war in Syria.
Recent Russian calls for all non-Syrian forces to leave southern Syria have been seen aimed partly at Iran, in addition to US forces based in the Tanf area at the Syrian-Iraqi border.
The town of Qusair was the scene of a major battle in the Syrian civil war in 2013 when Hezbollah fighters played a major part in turning the tide of the conflict in Assad's favour by defeating rebels.
Some details of the Qusair incident were reported by the Lebanese TV station Al-Mayadeen, which is close to Damascus and its regional allies such as Hezbollah. It said the number of Russian forces was small.
A military air base in the same area came under missile attack on 24 May. The Israeli military declined to comment on that attack.
Syrian rebel-held areas of southwestern Syria at the frontier with Israel have come into focus since Damascus and its allies crushed the last remaining besieged rebel pockets near the capital. Assad has vowed to recover all Syrian territory.
The United States wants to preserve a "de-escalation" zone that has contained the conflict in southwestern Syria. The zone, agreed last year with Russia and Jordan, has helped to contain fighting in areas near the Israeli frontier.