ASADABAD, Afghanistan — Taliban insurgents overran an Afghan National Army base near here Sunday morning, killing 21 soldiers in their bunks in what appeared to be the worst single blow to government forces since 2010, according to government and insurgent officials.
President Hamid Karzai ordered an investigation and canceled a planned state visit to Sri Lanka in response to the attack in the Ghaziabad district of Kunar province, near Pakistan.
The attack highlighted the vulnerability of Afghan military units, which are generally no longer accompanied by American or other NATO advisers and do not have the close air support they often enjoyed. And it raised questions about the Afghans’ ability to hold out against the insurgents on their own as the NATO mission winds down and international forces prepare to leave Afghanistan at the end of this year.
At the same time, there were signals that efforts to start peace talks with the insurgents were foundering. In an unusual statement released Sunday, the Taliban said they had suspended talks with the Americans aimed at a prisoner exchange: the release of five Taliban prisoners held at the Guantánamo Bay prison camp in exchange for the lone American prisoner of war held by the Taliban, Sergeant Bowe Bergdahl.
A Taliban spokesman, Zabiullah Mujahid, said that the talks had taken place with the mediation of Qatar, but that the insurgents had broken them off because of the “complicated political situation” in Afghanistan.
He did not elaborate but may have been referring to the presidential campaign or to Karzai’s continued refusal to sign a long-term security agreement with the United States.
Although the security deal was agreed to last year, Karzai imposed additional conditions, including US help in promoting peace talks with the insurgents. The Qatar-mediated talks — which took place over the past two months, according to Mujahid — may have been part of that.
The Taliban statement said that as part of the initiative, the insurgents had handed over a video showing Bergdahl was alive.
The prisoner exchange was intended as an initial confidence-building measure to get serious peace talks underway. On the battlefield, there has been little evidence that the Taliban have any other goal but to keep on fighting, and Sunday’s attack bolstered that impression.
The governor of Kunar province, Shuja al-Mulk Jalala, said it appeared infiltrators had let the Taliban insurgents into the base around 4 a.m. and most of those who died had been killed in their bunks. Jalala put the death toll at 20, with eight other soldiers reported to have been taken prisoner by the insurgents.
A spokesman for the Afghan Defense Ministry, General Zaher Azimi, later posted on Twitter to update the estimate to 21 dead and three wounded.
One of the Afghan soldiers taken prisoner, who later escaped and was interviewed in the eastern city of Asadabad, said he believed that the insurgents had entered the fortified base with the collusion of infiltrators who had been on guard duty in the base’s three watchtowers and outside its barracks.
He spoke on condition of anonymity because he was not authorized to speak to the news media.
Local Taliban officials, reached by telephone, denied that they had infiltrators in the base. “When US warplanes were over our heads, we conducted our operations successfully, and now that they no longer fly above us, we conduct our operations still more successfully,” said an insurgent official who spoke on condition of anonymity to protect himself from capture.
A statement from the Defense Ministry said the fighting with “local and foreign terrorists” lasted four hours. “These ANA soldiers resisted the enemy assault and fought to death against hundreds of both insider and outsider terrorists who assaulted them,” the statement said.
Reinforcements were sent to the area, but the soldiers were ambushed by insurgents using a suicide bomber.
“They were not hurt and reached the area to begin a counterattack to chase the enemy away,” the statement said.