Northern Syria (CNN) -- Undeterred by Syria's gruesome war of attrition, rebel fighters have scored a key gain where government forces once ruled.

The rebels have choked off a sprawling military base outside Aleppo with some 450 government soldiers trapped inside.

The rebels could easily overrun the base, fighter Ali Jadlan said. But they want to give government soldiers a chance to defect.

[link to www.cnn.com]