Blast in Afghanistan Kills 4 U.S. Soldiers

The U.S. military says an improvised explosive device has killed four American service members in southern Afghanistan.

U.S. military spokesman Lt. Cmdr. Christine Sidenstricker says the four were killed in the south in an explosion Tuesday. No other information was released pending the notification of family members.

The deaths bring to 41 the number of U.S. troops killed in Afghanistan this month, the second deadliest month in the country since the 2001 U.S. invasion. Last month a record 44 U.S. troops died.

General: More Troops in Afghanistan Means Less Risk

Violence has spiked the last three years, and the U.S. has more than 60,000 forces in the country, a record number.

CBS News' Lara Logan's coverage of Afghanistan:
For Afghans, All That Glitters is Not Gold
Marines Work and Live Hard in Afghanistan
Marines Walk Tightrope of Death
What the Afghans Really Want