A Syrian rebel brigade defected to Islamic State this week, a sign that the extremist group continues to build strength after seizing vast territories in western Iraq and eastern Syria, anti-government activists said.
The 1,000-strong Dawud Brigade, which had been based in Sarmin, a town in Syria's Idlib province, arrived on Sunday in Raqqa, a city in northeastern Syria that Islamic State has made its main headquarters for more than a year.
The defecting rebels moved in a convoy of more than 100 vehicles, including 10 tanks that had been seized from the Syrian army, the activists said on Tuesday. In order to cross the lines of pro-Western rebels who are fighting Islamic State, the defecting rebels said they were heading to Aleppo to confront government forces now attempting to lay siege to rebel-held parts of Syria's biggest city.
Dawud, with mostly Islamists in its ranks, has a complex history of relations with Islamic State, and the impact of its departure from an anti-government umbrella group the Sham Army was not immediately clear. The big question was whether other groups or individuals would follow suit.
Islamic State's leader, Abu Bakr al-Baghdadi, has called for Muslims around the world to travel to the Islamic caliphate the group has established in the areas of Iraq and Syria it controls.
The Sham Army claimed that it had expelled Dawud.