The State Department dismissed on Thursday Russia's claims that two American warplanes bombed the war-torn Syrian city of Aleppo.
The Russian Ministry of Defense claimed that two U.S. Air Force A-10 attack aircraft on Wednesday bombed nine targets in the city, which has been subjected to increased levels of violence in recent days.
The ministry said in a statement Thursday that the U.S. "did not make this mission public" and speculated that "perhaps there had been two hospitals" among the targets.
However, a senior State Department official told NBC News that the Russian claims were "false" and that there had been no U.S. missions over Aleppo on Wednesday or Thursday.
Russia's claims came a day after Pentagon spokesman Colonel Steve Warren accused Russian and Syrian forces of bombing Aleppo's two main hospitals.
The city is rapidly descending further toward humanitarian catastrophe as the Russian-backed Syrian regime intensifies its campaign of bombing and fighting against rebel groups.
More than 50,000 civilians have been forced to flee their homes during this renewed offensive in recent weeks, the UN High Commissioner for Human Rights, Zeid Ra'ad Al Hussein said on Thursday, calling it a "grotesque situation."
Russia claims it is bombing ISIS, which is also involved in the war, but Warren noted again Wednesday the Islamists were "virtually nonexistent in that part of Syria."