Tension in Kandahar after assassination

Afghan Police officers leave Police Substation 1 for a patrol in Kandahar City on July 13.</p>

Afghan Police officers leave Police Substation 1 for a patrol in Kandahar City on July 13.

KANDAHAR CITY, Afghanistan — In the wake of Tuesday’s assassination of Ahmed Wali Karzai, the president’s half brother and the most powerful man in Kandahar, and Thursday's suicide bombing of a mosque where his service was being held, U.S. and Afghan forces in Kandahar City are on a heightened state of alert.