One Marine killed , others wounded ; Taliban says 33 soldiers killed . 4,000 American troops , hundreds of Afghans involved in Operation Khanjar . It focuses on Helmand River valley , hotbed of Taliban violence . Comment:
One Marine killed , others wounded ; Taliban says 33 soldiers killed . 4,000 American troops , hundreds of Afghans involved in Operation Khanjar . It focuses on Helmand River valley , hotbed of Taliban violence . Operation 's size and scope are `` very significant , '' official says .