Russian warplanes began bombarding Syrian opposition targets in the war-torn nation's north Wednesday, following a terse meeting at which a Russian general asked Pentagon officials to clear out of Syrian air space and was rebuffed, Fox News has learned.

A U.S. official said Russian airstrikes targeted fighters in the vicinity of Homs, located roughly 60 miles east of a Russian naval facility in Tartus, and were carried out by a "couple" of Russian bombers. The strikes hit targets in Homs and Hama, but there is no presence of ISIS in those areas, a senior U.S. defense official said. These planes are hitting areas where Free Syrian Army and other anti-Assad groups are located, the official said.

Activists and a rebel commander on the ground said the Russian airstrikes have mostly hit moderate rebel positions and civilians. In a video released by the U.S.-backed rebel group Tajamu Alezzah, jets are seen hitting a building claimed to be a location of the group in the town of Latamna in the central Hama province.

The group commander Jameel al-Saleh told a local Syrian news website that the group's location was hit by Russian jets but didn't specify the damage.

A group of local activists in the town of Talbiseh in Homs province recorded at least 16 civilians killed, including two children.

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According to a U.S. senior official, Presidents Obama and Putin agreed on a process to "deconflict" military operations. The Russians on Wednesday "bypassed that process," the official said.

"That's not how responsible nations do business," the official said.

The development came after Pentagon officials, in a development first reported by Fox News, brushed aside an official request, or "demarche," from Russia to clear air space over northern Syria, where Moscow said it intended to conduct airstrikes against ISIS on behalf of Assad, according to sources who spoke to Fox News. The request was made in a heated discussion between a Russian three-star general and U.S. officials at the American Embassy in Baghdad, sources said. 

"If you have forces in the area we request they leave," said the general, who used the word "please" in the contentious encounter.

A senior Pentagon official said the U.S., which also has been conducting airstrikes against ISIS, but does not support Assad, said the request was not honored.

"We still conducted our normal strike operations in Syria today," the official said. "We did not and have not changed our operations."

"We still conducted our normal strike operations in Syria today"

- Senior Pentagon official

State Department spokesman John Kirby told reporters the Russian airstrikes won't change the strategy of the U.S.-led coalition. 

"The U.S.-led coalition will continue to fly missions over Iraq and Syria as planned and in support of our international mission to degrade and destroy ISIL," Kirby told reporters, while acknowledging the meeting at the American embassy in Baghdad.

Russia's Foreign Minister Sergey Lavrov told foreign ministers of world powers Wednesday that his country is "ready to forge standing channels of communication to ensure a maximally effective fight against terrorist groups."

Lavrov spoke to the U.N. Security Council shortly after Russia's defense ministry announced its jets are carrying out airstrikes on Islamic State group positions in Syria.

Lavrov said Russia would shortly circulate a draft council resolution to promote joint efforts against groups like the Islamic State.

The move by Moscow marks a major escalation in ongoing tensions between the two countries over military action in the war-torn country and comes moments after Russian lawmakers formally approved a request from Putin to authorize the use of troops in Syria. Putin said previously that Russia would strike ISIS targets. 

The Federation Council, the upper house of Russia's parliament, discussed Putin's request for the authorization behind the closed doors. Sergei Ivanov, chief of Putin's administration, said in televised remarks that the parliament voted unanimously to approve the request.

Ivanov said the authorization is necessary "not in order to achieve some foreign policy goals" but "in order to defend Russia's national interests."

Putin is obligated to request parliamentary approval for any use of Russian troops abroad, according to the Russian Constitution. The last time he did so was before Russia annexed Ukraine's Crimean Peninsula in March 2014.

Putin's request comes after his bilateral meeting with Obama on the sidelines of the United Nations General Assembly meeting in New York, where the two were discussing Russia's recent military buildup in Syria.

A U.S. official told Fox News Monday the two leaders agreed to discuss political transition in Syria but were at odds over the role that Assad should play in resolving the civil conflict. The official said Obama reiterated to Putin that he does not believe there is a path to stability in Syria with Assad in power. Putin has said the world needs to support Assad because his military has the best chance to defeat ISIS militants.

Putin said the meeting, which lasted slightly more than 90 minutes, was “very constructive, business-like and frank".

"We are thinking about it, and we don't exclude anything," Putin told reporters at the time

The Kremlin reported that Putin hosted a meeting of the Russian security council at his residence Tuesday night outside of Moscow, saying that they were discussing terrorism and extremism.

On Tuesday, French Foreign Minister Laurent Fabius called on Russia to make a real contribution to the fight against ISIS, telling reporters at the United Nations that Moscow "is against the terrorists, it's not abnormal to launch strikes against them."

"The international community has hit (ISIS). France has hit (ISIS), Assad very little, and the Russians not at all. So one has to look at who does what," Fabius added.

Russia has been a staunch supporter of Assad during Syria's bloody civil war, and multiple reports have previously indicated that Russian troops are aiding Assad's forces. Israel's defense minister also said earlier this month that Russian troops are in Syria to help Assad fight the ISIS terror group.

On Wednesday, Reuters reported that Russia's Foreign Ministry told the news agency Interfax that a recently established operations center in Baghdad would help coordinate airstrikes and ground troops in Syria. Fox News first reported last week that the center had been set up by Russian, Syrian and Iranian military commanders with the goal of working with Iranian-backed Shia militias fighting ISIS.

Over the weekend, the Iraqi government announced that it would begin sharing "security and intelligence" information with Russia, Syria and Iran to help combat ISIS.

Meanwhile, intelligence sources told Fox News Friday that Iranian Quds Force commander Qasem Soleimani met with Russian military commanders in Baghdad Sept. 22. Fox News reported earlier this month that Soleimani met Putin in Moscow over the summer to discuss a joint military plan in Syria. 

"The Russians are no longer advising, but co-leading the war in Syria," one intelligence official said at the time.

The Associated Press contributed to this report.