If this is true, and not a mistake, Obama has decided to come out openly in support of Islamic State:
Syria’s army general command said warplanes from the U.S.-led coalition bombed a Syrian army position at Jebel Tharda near Deir al-Zor airport on Saturday, paving the way for Islamic State fighters to overun it.
The air strike killed Syrian soldiers and was “conclusive evidence” that the U.S. and its allies support the jihadist group, the Syrian army said in a statement, noting that the strike was “dangerous and blatant aggression”.
Syria’s army controls Deir al-Zor airport and parts of the city which are otherwise entirely surrounded by territory held by Islamic State.
This would also appear to be in violation of the recent US-Russian ceasefire agreement.
UPDATE: The US admitted responsibility for the bombing.
The Obama administration officially expressed it’s “regret” for an airstrike that killed Syrian forces with a senior White House official saying “The United States has relayed our regret through the Russian Federation for the unintentional loss of life of Syrian forces.”