A close ally of Afghan President Hamid Karzai has been shot and killed in central Afghanistan, provincial government officials have said.
US and Afghan officials are concerned the Taleban may be regrouping
Haji Gilani and his nephew were killed as they left their home in the Deh Rawood district in Uruzgan province, its governor said.
Local police said they were investigating the incident, although so far no arrests have been made.
Governor Jon Mohammad told the Associated Press news agency that there was no evidence of a personal feud and he suspected that operatives from the country's former Taleban regime were behind the killing.
Gilani, who was in his 60s, sheltered Mr Karzai when he entered Afghanistan shortly after the 11 September 2001 attacks.
A recent decree called for a "jihad" against coalition forces in Afghanistan
The Afghan leader was forced to stay in hiding with anti-Taleban supporters, many of whom risked their lives to ensure his safety.
"When Karzai came back to Afghanistan for the first time, he was the only one who helped him," Mr Mohammad told French news agency AFP.
"He was the only one who really helped Karzai and was Karzai's personal friend."
Gilani's death follows a recent joint operation in the southern Afghan city of Kandahar by US and Afghan soldiers which left eight suspected Taleban fighters dead and a further 15 captured.
The bombing was in response to the growing concerns of Afghan and US officials that Taleban forces are regrouping after they were driven from power 18 months ago, and attempting to destabilise the country.
On Friday an aid worker with the International Committee of the Red Cross was shot dead, also in the Uruzgan province.
A recent edict allegedly by the deposed Taleban regime's supreme leader, Mullah Mohammed Omar, also urged Afghans to take part in a jihad - or holy war - against coalition forces in the country.
Afghan Interior Minister, Ali Ahmad Jalali, has said that increased Taleban activity may be linked to the current US-led war in Iraq.