U.S. F-16 fighters
U.S. F-16 fightersReuters

The US led coalition halted air strike mission in eastern Syria on Saturday that 'unintentionally' and 'mistakenly' killed unverified number of Syrian government soldiers. The incident also prompted an emergency United Nations security council meeting amid escalating tensions.

Though the Russian military said that the strike in Syria's Deir Ezzour province, killed 62 Syrian soldiers and wounded more than 100 people, based on information received from the Syrian command, the Syrian Observatory for Human Rights, suggested that the strike killed at least 83 Syrian troops.

Syrian state news agency Sana said two A-10 ground-attack planes and two U.S. F-16 fighters took off from Iraq to conduct the strike.

In a statement in the aftermath of the incident on Saturday, the U.S. Central Command said the air attack "was halted immediately when coalition officials were informed by Russian officials that it was possible the personnel and vehicles targeted were part of the Syrian military."

American military officials said the pilots in the attack believed they were targeting the Islamic State and added that the coalition had informed Russian officials about the strike beforehand.

"It is not uncommon for the Coalition Air Operations Center to confer with Russian officials as a professional courtesy and to deconflict coalition and Russian aircraft, although such contact is not required by the current US-Russia Memorandum of Understanding on safety of flight," the US statement said.

Senior administration officials said the U.S. has relayed "regret" to Syrian President Bashar al-Assad's government through Russia "for the unintentional loss of life of Syrian forces fighting ISIL."

However, the Syrian government did not consider the strike as a mistake. Instead, government said the air strike was "a very serious and flagrant aggression" that aided the Islamic State and proved its long-held assertion that the United States supports the jihadist group as part of an effort to oust President Bashar al-Assad.

The Syrian Army Command said that American warplanes had bombed an army base on Al-Tharda mountain at 5 pm, allowing "a wide terrorist offensive" by the Islamic State that allowed it to seize the base according to the New York Times.

"These attacks confirmed that the U.S. clearly supports the terrorism of Daesh," SAMA television, a state-run news outlet said, while quoting a statement issued by the Syrian military's general command, which said the attack exposed "false claims of fighting terrorism" by the United States.

US central command denied the charges that the strike was intentional and thus began a bitter squabble of words between the stakeholders–Washington, Moscow, and United Nations, while the fragile cease-fire deal brokered last weekend hangs in the balance.

Escalating diplomatic tensions

Russia called for an emergency meeting of the U.N. Security Council on Saturday night, and its envoy accused the U.S. of violating its commitments under the cease-fire by bombing Syrian forces.

Reacting to Russia, Samantha Power, the United States ambassador to the United Nations, accused their counterpart of pulling a "stunt" and added that it reflected on their hypocrisy of not highlighting human right violations conducted by the Assad regime, while Vitaly Churkin, the Russian U.N. envoy, dismissed Power's statement as "demagoguery of the highest order."

Vitaly Churkin also answered vaguely when asked if the incident would spell the end of the Syria deal between Moscow and Washington

"This is a very big question mark." he said. "I would be very interested to see how Washington is going to react. If what Ambassador Power has done today is any indication of their possible reaction, then we are in serious trouble," Churkin told reporters.

Russia also reiterated and continued the Assad regime's rhetoric, suggesting that the US is aiding the Islamic State.

"We are reaching a really terrifying conclusion for the whole world: That the White House is defending Islamic State. Now there can be no doubts about that," the RIA Novosti news agency quoted Russian Foreign Ministry spokeswoman Maria Zakharova as saying.

Power said Zakharova should be embarrassed by that claim, while Churkin said Russia had no "specific evidence" of the United States colluding with Islamic State militants. The details of the UN meeting have not yet emerged.