Damascus (AFP) - A Syrian military helicopter was shot down over the last major rebel bastion in northwest Syria on Friday, the second such incident in a week of high tensions with Turkey.
The attack in a region where Turkish troops and Russian-backed government forces have engaged in multiple clashes came as Washington urged Ankara to look to its Western allies in light of Moscow's actions.
It came as Syrian and Russian forces pressed a deadly offensive against the shrinking pocket in the country's northwest, claiming the lives of nine civilians on Friday.
"At approximately 13:40 (1140 GMT), one of our military helicopters was hit by a hostile missile in the western countryside of Aleppo," Syrian state news agency SANA said.
"This led the helicopter to crash, killing all crew on board."
SANA said the aircraft was downed near the town of Urum al-Kubra, where Turkey-backed rebels operate, but did not say who was behind the attack.
The Turkey-backed National Liberation Front rebel group claimed responsibility in a statement posted on the Telegram app.
The Syrian Observatory for Human Rights said two pilots were killed in the downing of the helicopter.
An AFP correspondent saw the mangled remains of the chopper and the blood-stained fatigues of one of the pilots.
Three days earlier another Syrian military helicopter was downed over Idlib province, killing at least three crew members.
Turkish media blamed that attack on rebels but the Observatory said Ankara's troops had fired rockets at the aircraft over the village of Qaminas, southeast of Idlib city.
Turkey did not claim responsibility.
- Turkey tensions -
Since December Syrian government forces have pressed a blistering assault on the last major rebel pocket in the northwestern Idlib region and parts of neighbouring Aleppo and Latakia provinces.
Eight civilians including three children were killed in bombardment Friday, the Observatory said, adding that five died in Russian raids near the deserted city of Atareb.
Government forces are within five kilometres (three miles) of the city, the monitor said.
The assault has sparked the largest wave of displacement in the nine-year conflict, with 800,000 people fleeing since December, according to the United Nations.
Among them, some 82,000 people are sleeping rough in sub-zero temperatures.
The unprecedented exodus has triggered alarm in Turkey, which fears an influx across its border.
Turkey first sent troops to Syria in 2016 and has sent reinforcements to the northwest in recent weeks to contain the assault.
That has lead to a series of confrontations, including deadly clashes this week which saw government shelling kill five Turkish troops.
Turkish President Recep Tayyip Erdogan has threatened the Syrian government in recent days, saying the offensive violates a 2018 deal with Russia meant to prevent a broad military operation.
The advance has also escalated tensions between Ankara and Moscow, who have worked closely together despite backing opposing sides in Syria.
Erdogan on Wednesday accusing Russia of committing "massacres" in Idlib.
- Russian 'destructive role' -
A senior US State Department official said Friday that tensions between Turkey and Russia over Syria should prompt Ankara to move closer to the West, especially Washington.
"Certainly we would like to see Turkey more directly and clearly aligned with NATO, the United States, the West, in recognition of the very destructive role that the Russians are playing regionally, including right now in Syria," the official said.
"There is much more overlap between Turkish interests and US interests," he added. "Turkey's ally is the United States, not Russia."
On Friday, pro-government forces pushed west of the key M5 motorway, which connects Syria's four largest cities and is economically vital for the government, the Observatory said.
Syrian forces seized the last segment of the highway still out of their control earlier this week. SANA said Friday that the areas flanking it had been swept and the road fully secured.
To consolidate a "security belt" around the road, the regime seized a key base on Friday that it had lost to rebels in 2012, the Observatory said.
Located 12 kilometres (seven miles) west of Aleppo city, Base 46 was the site of a brutal confrontation between government forces and rebels in the early phase of Syria's civil war.