The powerful half-brother of Afghan President Hamid Karzai was slain Tuesday, raising immediate questions about the motive behind his assassination.

Ahmed Wali Karzai, 50, was shot in the head and chest by a bodyguard, while he was signing papers inside his heavily fortified compound in Kandahar.

Provincial police chief Brig.-Gen. Abdul Razik said Karzai's security team shot and killed the suspected gunman, who has since been identified as Sadar Mohammed. The guard was said to be was well known to the Karzai family.

Karzai's body was taken to the Mirwais hospital in Kandahar for formal identification after he was shot.

Razik said police have yet to determine the motive behind Karzai's killing, though the Taliban quickly claimed that they had recruited the gunman involved in the fatal attack.

CTV's South Asia Bureau Chief Janis Mackey Frayer said that while no proof has emerged to verify the Taliban's claim, the shocking murder of the president's half-brother is making many Afghan officials uneasy about their own safety.

"There is a sense that there will be more instability as international troops begin to withdraw," Mackey Frayer told Â鶹´«Ã½ Channel from Kabul on Tuesday.

"Afghan officials are feeling far more vulnerable."

The assassination occurred just hours before the Afghan president held a press conference with French President Nicolas Sarkozy in Kabul.

"This morning, my younger brother Ahmed Wali Karzai was murdered in his home," Hamid Karzai told reporters Tuesday.

"Such is the life of Afghanistan's people. In the house of the people of Afghanistan, each of us is suffering and our hope is that, God willing, to remove this suffering from the people of Afghanistan and implement peace and stability."

Canada's Ambassador to Afghanistan, H.E. William Crosbie, condemned the killing and offered Canada's condolences to President Karzai and their family.

"Canada will continue to work with Afghans, the majority of whom reject senseless violence, to build a better governed, more stable and secure country free of conflict," Crosbie said in a statement.

Bismullah Mohammadi, the Afghan interior minister, said Ahmed Wali Karzai was "a loyal and faithful servant" to his people.

"This is truly a sad day for all," Mohammadi said. "Mr. Karzai will be remembered and honoured for his selfless dedication and commitment to peace and stability."

Karzai had survived at least nine prior attempts on his life, which prompted him to travel in the company of bodyguards and provincial police.

He had led the provincial council in Kandahar for years, landing the position a few years after his brother took over as Afghan president following the 2001 U.S. invasion.

But he was a controversial figure in Afghan society, as he was long accused of corruption and involvement with the CIA and the drug trade -- claims that he denied were true. U.S. diplomats long considered Karzai a disruptive influence and previously lobbied the Afghan president to move him out of his role in Kandahar. But Hamid Karzai demanded proof of the allegations against his half-brother, who stayed in his position until his death on Tuesday.

"He held all the cards: he had political power, economic power because he had his hand in so many types of businesses," Mackey Frayer said.

"There was a degree of clout. He had the respect of some and he was feared by others."

Rangina Hamidi, the daughter of the mayor of Kandahar, said the slain Karzai is survived by three daughters and two sons -- including one son who was born only a month ago.

"It is his one-month-old child who is never going to see his father that I cry about," Hamidi told The Associated Press, sobbing during a telephone interview. "How many orphans and widows are we creating in this country?"

With files from The Associated Press and The Canadian Press