WASHINGTON (Reuters) - Thousands of U.S.-backed fighters in Syria are launching an offensive to capture from Islamic State a crucial swathe of northern Syria known as the Manbij pocket following weeks of quiet preparations, U.S. officials disclosed to Reuters.
The operation, which only just started to get underway on Tuesday and could take weeks to complete, aims to choke off Islamic State's access to Syrian territory along the Turkish border that militants have long used as a logistics base for moving foreign fighters back and forth to Europe.