Syrian Rebel Infighting Kills 5 Near Iraqi Border Al-Qaida-affiliated rebels battled more moderate Syrian opposition fighters in a town along the Iraqi border on Saturday, killing at least five people in the latest outbreak of infighting among the forces opposed to President Bashar Assad's regime. Clashes between rebel groups, particularly pitting al-Qaida-linked extremist factions against more moderate units, have grown increasingly common in recent months, undermining the opposition's primary goal of overthrowing Assad. The Britain-based Syrian Observatory for Human Rights said Saturday's fighting took place in the town of Boukamal between the al-Qaida-linked Islamic State in Iraq and the Levant against more mainstream rebel groups. Observatory director Rami Abdul-Rahman said the more moderate rebels used mosque loudspeakers Friday to demand the Islamic State in Iraq and the Levant leave Boukamal. When it was clear Saturday the ISIL had no plans to decamp, the mainstream groups attacked, Abdul-Rahman said. Three mainstream rebels and two ISIL fighters were killed in the clashes, he said. It was not immediately clear what spurred the rebel demands for ISIL to leave Boukamal. After months of growing tensions, infighting among Syria's mosaic of rebel factions broke into the open in July. For a time, the clashes contributed to a sense that the rebellion was faltering, and threatened to fracture an opposition movement that has been plagued by divisions from the start. The moderates once valued the expertise and resources that the Islamic extremist brigades brought to the battlefield, and rebel factions of all stripes enter into occasional alliances for specific operations. But many of the moderates now question whether such military assets are worth the trouble - not to mention the added difficulty in persuading the West to arm them.