Here is a look at the main developments Tuesday in the U.S.-led coalition's campaign against militants from the Islamic State group.
— Warplanes from the U.S. and Arab allies strike Islamic State group positions in Syria for the first time, hitting training camps and other facilities. Saudi Arabia, Bahrain, the United Arab Emirates and Jordan confirm they participated in the strikes. Qatar played a supporting role. Among the targets hit was a government building used by the militants as a headquarters in their de facto capital, the Syrian city of Raqqa.
— U.S. strikes also hit al-Qaida's branch in Syria, targeting a cell known as the Khorasan Group said to be plotting to attack the United States or Europe. Lt. Gen. William Mayville said the group was nearing the "execution phase" but that it was too early to tell if the strikes disrupted the plot.
— President Barack Obama said that Arab support for the airstrikes "makes it clear to the world this is not America's fight alone."
"We're going to do what's necessary to take the fight to this terrorist group, for the security of the country and the region and for the entire world," Obama said as he left Washington for meetings of the U.N. General Assembly in New York
— Activists in Syria report that some of the targets hit in the strike were empty, particularly buildings in Raqqa, because militants left them to hide among the civilian population in recent days. Casualties from the strikes remain unconfirmed, but Syrian activists report casualties among Islamic State fighters.
— Syrian President Bashar Assad says he supports any international campaign against terrorism, giving an indication of acquiescence to the strikes. In past weeks, Syrian officials have said any attacks on the militants should be coordinated with Assad's government, something Washington refused.
— Still, Syria's top allies, Iran and Russia, condemn the strikes. Russia says the "unilateral" strikes will destabilize the region. Iran says strikes without the Syrian government's permission are "unacceptable."