According to the Russian Ministry of Defense, two F-16 fighter jets and two A10 ground attack aircraft that entered Syrian airspace from Iraq launched airstrikes against the SAA base in the city of Deir ez-Zor, leaving at least 62 Syrian servicemen killed and more than 100 wounded.
First Deputy Chairman of the Defense and Security Committee in Russia's Federation Council Franz Klintsevich maintained that what happened in Deir ez-Zor on Saturday was not an accident.
"The US conducted airstrikes on government forces in Syria deliberately and thoughtfully. Any aerial operation is coordinated with commanders on the ground. In this case [the US] used information received from their intelligence units who infiltrated Daesh," he told RIA Novosti.
The airstrike on the SAA in Deir ez-Zor, he added, reflected America's double standards.
'Assad must go': Washington's only goal in Syria
The senator also suggested that the attack could have been "a provocation, a desire to see how we will react." Klintsevich further said that the United States is not really interested in destroying the brutal group that still controls large parts of Iraq and Syria.
Russian envoy to the UN Vitaly Churkin was wary of the timing of the attack. "It is highly suspicious that the United States chose to conduct this particular air strike at this time," he said.
If the US wanted to help Damascus-led forces defending Deir ez-Zor, "it could have waited several days until the agreement reached by Sergei Lavrov and John Kerry in Geneva on the joint implementation center entered force," the diplomat noted.
Churkin also said that "some aspects of the situation suggest that it could have well been a provocation." However, he also said that the attack did not mean that the ceasefire deal was over.
The Russian Defense Ministry spokesman, Maj. Gen. Igor Konashenkov, noted that if the airstrike was an accident, it was "a direct consequence of the US' unwillingness to coordinate its actions against terrorist groups with Russia."
'Undermining' the Lavrov-Kerry ceasefire deal
The airstrike on the Syrian Arab Army in Deir ez-Zor risks undermining the Geneva agreements, Klintsevich said.
Klintsevich also said that Russia and the US have pursued different interests in Syria. "Their interests do not overlap with ours and vice versa."
US has jeopardized the peace process in the Middle East
Russian MP Sergei Gavrilov went even further, saying that the US-led coalition's attack ruined the deal unveiled on September 9.
"I think that the United States has derailed the agreements that Lavrov and Kerry tried to reach. As a result, Washington has jeopardized the peace process in the Middle East," the lawmaker told RIA Novosti.
The Russian lawmaker further said that US airstrikes in Syria could pose a major threat to the Russian military base. "This is why we need to demand that the US adheres to the agreement and drastically enhance our aerial defense capabilities in Syria to provide security to our bases," he noted.
"I think that our air defense forces and the Russian Aerospace Forces have enough combat capabilities to prevent the US Air Force from flying over Syria," he added.