Russia launched fresh airstrikes on rebel positions in Syria on Thursday, having already been forced to deny the country's first wave of attacks have killed 36 civilians.
The latest bombardment from Russia's military comes the day after the US raised concerns those being targeted were opponents of Syrian President Bashar al-Assad — rather than Islamic State (IS) militants.
The strikes were reportedly targeting areas including rural areas near the northwestern town of Jisr al-Shughour, held by an alliance of insurgents including al Qaeda's Nusra Front, Lebanon-based al-Mayadeen TV said, according to Reuters.
Two members of a rebel brigade operating in Talbiseh told VICE News via phone that fast jets of a kind they'd never seen before hit the town between 1pm and 2pm causing dozens of casualties including civilians and children.
"The regime has bombed this area many times before, but not heavy like yesterday," one said, adding that the attack was of a severity they hadn't experienced before. "We didn't guess that it would be this strong. We knew there would be bombing from Russia, but we didn't think it would be like this."
Another said they did not expect, nor want, help or assistance from the US, but hoped that Saudi Arabia might step in after officials condemned the Russian strikes.
The jets carried out at least 30 strikes targeting the "Army of Conquest," it said in a newsflash. The strikes targeted the militants, a newsreader from the pro-Damascus channel said.
The channel said strikes also hit other areas in Idlib province, including the Zawiya Mountain region, as well as areas in Hama province further south. The pro-opposition Orient News channel said Russian strikes hit rebel positions in the Hama countryside.
The Army of Conquest had made gains in northwestern Syria alongside other insurgent groups since May, seizing Idlib city and Jisr al-Shughour from government forces and advancing towards the coastal areas.
Idlib is of greater strategic importance due to its proximity to President Bashar al-Assad's heartland in Latakia province on the Mediterranean coast.
Russia began air strikes in Syria on Wednesday in a major escalation of the more than four-year conflict, hitting rebel groups in the country's west, including Homs province. Local activists claimed that rather than targeting IS, the strikes hit rebel positions in Talbiseh and elsewhere.
The head of Syria's main opposition group said that dozens of civilians, including children, have allegedly been killed in the first wave of Russian airstrikes — claims that have been rejected by Moscow.
"The Russians struck northern Homs today and killed 36 innocent people... Who fought against extremism," said Khaled Khoja, head of the National Coalition, in an interview.
"It's obvious today's attack on civilians showed clearly that the Russians' aim [is] not to fight ISIS [or IS], it's to prolong the life of the Syrian regime," he added.
On Twitter, a member of the Army of Conquest said "the alliance of Russian pigs launched its operations... by destroying a mosque in Jisr al-Shughour and flattening it," AFP reported.
But a spokeswoman for Russia's foreign ministry dismissed the accusations, claiming Russia is adhering "absolutely, legitimately" to international law.
Putin secured the parliament's unanimous backing to launch airstrikes against IS militants in Syria on Wednesday, paving the way for imminent Russian military intervention in its closest Middle East ally.
The vote, which sets the stage for Russia's biggest play in the region since the 1991 collapse of the Soviet Union, was announced as Syrian government warplanes conducted heavy strikes in Homs province and the United States and its allies struck IS targets.
A Syrian government military source said on Thursday that Russian military support would bring a "big change" in the course of the four-year war, particularly through advanced surveillance capabilities that could pinpoint insurgent targets.
"There will certainly be a big change on the course of field developments, by virtue of the advanced technologies and weapons the Russian army has ... particularly in surveillance and identifying targets," the source said.
"Perhaps the biggest change that will happen is via the capabilities the Russians have in identifying coordinates of the locations of terrorist groups, particularly the headquarters of their leaders, and their movements."
As part of its preparations, Moscow has already sent military experts to a recently established command centre in Baghdad which is coordinating air strikes and ground troops in Syria, a Russian official told Reuters on Wednesday.
The Russian Defense Ministry said the center is used to share information on possible air strikes in Syria.
Sergei Ivanov, the Kremlin's Chief of Staff, said Russia's missions would be limited and not open-ended and precluded the use of ground troops.
A proposal enabling Russia to use armed forces beyond its territory has been submitted to the Federation Council— President of Russia (@KremlinRussia_E) September 30, 2015
"As our president has already said, the use of ground troops has been ruled out. The military aim of our operations will be exclusively to provide air support to Syrian government forces in their struggle against ISIS (or IS)," he said.
The decision to get involved militarily in Syria will be a further challenge for Moscow, which is already intervening in Ukraine at a time when its economy is suffering from low oil prices and Western sanctions.