(BBC News)-- The half-brother of Afghan President Hamid Karzai has been assassinated in Kandahar, officials say.
Ahmad Wali Karzai, a leading power broker in the country's south, was shot dead at his home in a blow to Nato's battle against the Taliban in the area.
He was shot twice by his long-time head of security Sardar Mohammed, who was himself killed almost immediately.
The Taliban said they carried out the attack, calling it one of their top achievements in 10 years of war.
Sardar Mohammed's motives remain unclear, but the killing will raise questions about securing Afghanistan's top officials. His is the latest and most high-profile in a series of assassinations of senior politicians and security commanders across the country.
The Afghan president said the assassination reflected the suffering of all Afghan people.