General David Petraeus, the U.S. commander in Afghanistan and most celebrated military leader of his generation, stepped down on Monday after a checkered year at the helm of what is America's longest war.

At a ceremony in Kabul Petraeus passed the baton to John Allen, a former subordinate who made his name in Iraq by striking tribal alliances considered integral in reversing al-Qaida's momentum after years of appalling violence.

The Taliban on Monday claimed the overnight killing of one of Afghan President Hamid Karzai's key advisers, who died along with a lawmaker in an attack on his home in Kabul.

Jan Mohammad Khan, the former governor of southern Uruzgan province and a key ally of the embattled president, was killed along with an MP for Uruzgan.

NATO said Friday it would investigate Afghan claims that six civilians were killed during a military operation targeting the al-Qaida-linked Haqqani network.

Provincial government officials said the six, one of them an 11-year-old girl, died during an operation on Thursday in the eastern province of Khost.

A suicide attack on Thursday struck memorial prayers for the assassinated brother of the Afghan president, killing four people including a senior cleric in a mosque, officials said.

Interior ministry spokesman Siddiq Siddiqi said 13 people were also wounded when the bomber blew himself up in the southern city of Kandahar, where cabinet ministers visiting from the capital Kabul had been in attendance.

Afghan President Hamid Karzai Wednesday renewed his call on the Taliban to make peace, even as he buried his brother whose assassination was claimed by the militia.

A grieving Karzai led thousands of mourners at the funeral of his brother, Ahmad Wali Karzai, who was assassinated at his home in southern Kandahar city by his own head of security on Tuesday.

A bomb attack on Wednesday hit the motorcade of a key Afghan governor en route to the funeral of President Hamid Karzai's brother, wounding two Afghan troops, the government said.

The governor of Helmand province, Gulab Mangal, and the provincial chief of Afghan intelligence escaped unhurt, said an official statement, and the group attended the funeral of Ahmed Wali Karzai in neighbouring Kandahar province.

Ahmed Wali Karzai, the younger brother of the Afghan president and a deeply controversial power broker in the country's southern Taliban heartland, was assassinated at home on Tuesday.

The killing will present a huge loss for President Hamid Karzai in Kandahar, the heartland of the insurgency as NATO troops start withdrawing combat troops and search for a political solution after a decade of war.

President Nicolas Sarkozy said Tuesday that France would withdraw a quarter of its 4,000 troops from Afghanistan by the end of next year, becoming the latest NATO power to downsize its combat mission in the war-torn country.

The French leader announced the withdrawal after jetting in on a surprise visit to meet troops stationed in Sarobi district, northeast of Kabul, and to be briefed on progress against the Taliban by a French general.

President Hamid Karzai advised Afghans not to hold extravagant wedding parties saying in his weekly radio address to the nation on Friday that they were "against the national tradition."

Since the fall of the Taliban nearly a decade ago, marriage ceremonies in Afghan cities have often gone from being simple family affairs to lavish parties for up to 1,000 people in neon-clad wedding halls.

Afghanistan's central bank governor has resigned and fled to the United States, saying his life is in danger over a corruption probe targeting influential figures connected to the government.

President Hamid Karzai's government on Tuesday dismissed the claims of Abdul Qadir Fitrat, chairman of Da Afghanistan Bank, insisting his life was not under threat and calling him a "runaway governor".