Hamidullah Nawroz, a provincial council member from Ghazni, said the Humvee was accompanied by several gunmen on foot. The assault began just after 8 a.m. when gunmen fatally shot the guards at the security compound, clearing the way for the Humvee to enter and then detonate.
Nawroz said the base, home to an elite unit of Afghanistan's security forces and other government-aligned fighters — was completely destroyed. The base sits just east of the provincial capital in Ghazni, 90 miles southwest of Kabul.
No group immediately claimed responsibility for the attack. As of Sunday night, the Taliban had not issued a statement denying involvement, as it does normally. But some local officials were already blaming the group, citing its history of carrying out such attacks.
President Ashraf Ghani condemned the attack. The country’s “security and defense forces must urgently counter the enemy’s threats,” he said in a statement released by his office.
Afghan government negotiators in Doha say a cease-fire remains a top priority in the talks with the Taliban. But since the ceremony launching the peace initiative in September, little progress has been made. Reports emerged last week of a potential breakthrough, only to have government officials say details remain under discussion.
A deal signed by the United States and the Taliban this year brought a near end to large-scale Taliban-claimed attacks in Afghanistan’s urban areas. Most large-scale attacks in those areas, including one that killed 22 people at a university in Kabul, most of them students and teachers, have been claimed by the Islamic State militant group.
But in rural areas, clashes between Taliban fighters and government forces are on the rise. Each side has accused the other of trying to expand the territory under its control.
Afghan government forces have come under increased pressure as U.S. forces withdraw from the country and Taliban fighters launch major offensives on government-held districts and towns.
The United States has closed at least 10 bases across Afghanistan ahead of a fast-approaching deadline for an accelerated withdrawal. In a departure from the public text of the deal signed with the Taliban, the Pentagon announced that the United States will draw down to 2,500 troops by Jan. 15.
Many Afghan government officials fear that an expedited U.S. withdrawal will further embolden the Taliban and destabilize the country.
The provinces that have borne the brunt of increased violence in recent months are those where Taliban fighters have significant control and influence. Ghazni, which sits on a key highway that connects the Afghan capital to the country's south, is one of the least stable provinces in Afghanistan. Roughly two-thirds of its districts are controlled or contested by the Taliban.
Government forces retook three districts from the Taliban in Ghazni last year but even those gains were fragile. Many civilians said they remained in danger even after government declarations of victory.
George reported from Islamabad, Pakistan. Sharif Hassan in Kabul contributed to this report.