KABUL, Afghanistan — Afghan President Ashraf Ghani has ordered Gen. Hibatullah Alizai to replace Gen. Wali Ahmadzai as the Afghan Army chief of staff, according to local media reports and an Afghan defense official who spoke to The Associated Press.

The Defense Ministry official spoke on condition of anonymity because the decision had yet to be made public.

Alizai was the commander of the Army’s Special Operations Corps — the elite troops that, along with the Air Force, have been forced to do most of the fighting as regular forces have collapsed amid a Taliban advance.

The Taliban seized three more provincial capitals in Afghanistan and a local army headquarters, officials said Wednesday, completing their blitz across the country’s northeast and pressing their offensive elsewhere. The insurgents now control some two-thirds of the nation as the U.S. and NATO finalize their withdrawal after a decades-long war there.

The fall of the capitals of Badakhshan and Baghlan provinces to the northeast and Farah province to the west put increasing pressure on the country’s central government to stem the tide of the advance, even as it lost a major base in Kunduz.

Ghani rushed to Balkh province, already surrounded by Taliban-held territory, to seek help in pushing back the insurgents from warlords linked to allegations of atrocities and corruption.

While the capital of Kabul has not been directly threatened in the advance, the stunning speed of the offensive raises questions of how long the Afghan government can maintain control of its countryside. The multiple fronts of the battle have stretched the government’s special operations forces — while regular troops have often fled the battlefield — and the violence has pushed thousands of civilians to seek safety in the capital.

The U.S. military, which plans to complete its withdrawal by the end of the month, has conducted some airstrikes but largely has avoided involving itself in the ground campaign. The Afghan government and military did not respond to repeated requests for comment about the losses.

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