Two Marines killed during a `` hostile incident '' in southern Afghanistan . No further details were immediately available in their deaths . 4,000 U.S. Marines , sailors working to clear Taliban militants from Helmand river valley . U.S. Marines forces launched a similar offensive in the province in August . Forces are trying to gain ground in the region ahead of national elections in late June .
Two Marines killed during a `` hostile incident '' in southern Afghanistan . 4,000 U.S. Marines , sailors working to clear Taliban militants from Helmand river valley . U.S. Marines forces launched a similar offensive in the province in August . Forces are trying to gain ground in the region ahead of national elections in late June .