A Kurdish militia that has captured swathes of northern Syria from Islamic State has signed up thousands of fighters in recent months as it seeks to tighten control over newly won territory.

The People’s Protection Units (YPG), which has been fighting Islamic State with U.S.-led air support, says it now controls territory the size of Qatar and Kuwait combined.

YPG spokesman Redur Xelil, speaking to Reuters, said the YPG had drawn 5,000 new recruits, growing to 40,000 fighters. After a period of rapid territorial gains, the priority was to strengthen defensive positions in newly captured land. […]