KABUL, Afghanistan — At least 23 soldiers were killed while they were sleeping on Saturday in an insider attack in eastern Afghanistan, officials said, the latest episode of enemy infiltration that has raised concerns about a new local military force billed as the hope for holding territory recaptured from the Taliban.
The Taliban infiltrator, who was on duty at a military base in Ghazni Province, opened fire on his colleagues, wiping out almost the whole unit, officials said. The attacker then seized all weapons and equipment in the base and joined the insurgency.
The exact number of casualties was unclear. The Afghan Ministry of Defense confirmed the death of nine soldiers, and the Taliban said 32 had been killed, but their claims of casualties are mostly exaggerated.
The figure of 23 came from Esmatullah Jamuradwal, a member of the provincial council, who said that only one soldier, out of 24 in the Territorial Army unit, had survived. “The attacker packed all weapons and ammunition in a Humvee and drove to the Taliban,” he said.
A spokesman for the Ministry of Defense said that officials had begun an investigation into the attack.
This was the second deadly attack by an infiltrator in the Territorial Army in the Qara Bagh District of Ghazni. In July, Col. Abdul Mobin Mohabati, the commander of the Afghan Army forces in the provinces, was killed by such an infiltrator.
This past week, as Taliban negotiators resumed peace talks with American diplomats, militants set off a car bomb and penetrated a medical facility attached to Bagram Air Base, killing at least two people and wounding at least 73.
But civilians continue to be the main victims of Afghanistan’s nearly two-decade war. On Friday, 10 were killed and six others wounded when a roadside bomb placed by the Taliban hit a shuttle bus in the Jaghatu District of Ghazni, officials said.
The latest insider attack has raised doubts about the Afghan Territorial Army, through which the government hopes to hold areas they had retaken from the Taliban. Members of the Territorial Army are local people trained by the regular Afghan Army. The screening process is less strict than for the regular army, and the local force is seen as cheaper to maintain since those who sign up don’t need the same logistics and supplies as members of the regular army.
According to defense officials, close to 7,000 members of the Territorial Army have been recruited and trained, mostly in volatile areas where the Afghan government had made territorial gains.
Battlefield gains are particularly important this fighting season in order for both sides to get more leverage at the negotiation table. After Afghan forces push back the Taliban from certain areas, they have always struggled to hold the recently cleared territory.
The recent round of talks between the chief United States peace envoy, Zalmay Khalilzad, and Taliban representatives in Doha, the Qatari capital, had tackled decreasing the violence, a possible cease-fire and paving a path for talks between insurgents and the Afghan government. But the talks were paused on Friday after five days so that the Taliban negotiators could consult with their leaders.
President Trump abruptly called off peace talks in September, after a Taliban attack. He announced the resumption of negotiations in November, during his first visit to Afghanistan. Mr. Trump said the Taliban were interested in a cease-fire, but his remarks appeared to catch the militants off guard.
Mujib Mashal contributed reporting.