The Washington Post reports:

The half-brother of Afghan President Hamid Karzai was assassinated by one of his security guards inside his house in Kandahar on Tuesday morning, a political killing that will reverberate widely through the country and could destabilize a key region in the U.S. military’s campaign against the Taliban, according to witnesses and Afghan officials.

Ahmed Wali Karzai, the head of Kandahar’s provincial council who was widely considered the most powerful man in southern Afghanistan, had been meeting with tribal elders and politicians in his heavily fortified home in downtown Kandahar city when a security guard walked into his meeting room and requested a private discussion, according to two people at the house at the time. Karzai and the guard left for another room, and shortly afterwards three gunshots rang out.