Overstretched Afghan forces are pulling back from violent southern districts without a fight, ceding key territory to the resurgent Taliban as part of an unprecedented "strategic retreat" that has stoked fears government control is slipping, AFP reports.

Beset by record casualties, desertions and troop shortages, Afghan troops have recently abandoned outposts in parts of central Uruzgan province, extending a withdrawal which began last month.

The retreat has triggered fevered speculation about possible government backroom deals with the Taliban at a time when international efforts are growing to bring the insurgents to the negotiating table.