Afghan officials accused NATO of killing civilians in an airstrike that left at least 10 dead in the country's remote east, while the Taliban on Sunday staged a car bomb and gun attack outside an intelligence office, killing four soldiers and injuring more than 80 people.

Both incidents underscored the chronic insecurity in Afghanistan as U.S.-led foreign forces reduce their presence and hand over more responsibilities to Afghan troops.

Conflicting reports emerged from the airstrike in the Watapur district of Kunar, a province that lies along the border with Pakistan. The territory is dangerous and difficult to reach, and many Arab and other foreign insurgents are believed to operate there alongside the Afghan Taliban. Some are suspected to have links to al-Qaeda.

Kunar province police chief Abdul Habib Sayed Khaili said the airstrike hit a pickup truck carrying women and children in Qoro village soon after three Arab and three Afghan militants boarded it Saturday evening. He said some residents called it a drone strike, which would not be unusual in that area.

The police official put the total dead at 15, saying four were women, four were children and one was the civilian driver. But Afghan President Hamid Karzai's office later put the death toll at 16, saying only that women and children were among the victims.

As he has in the past, Karzai strongly condemned the killing of civilians and offered condolences to their families.

NATO spokeswoman 1st Lt. AnnMarie Annicelli said the military alliance carried out a "precision strike" that killed 10 "enemy forces," but that it had received no reports of any civilians dying. Annicelli would not comment on whether a drone was used, and had no immediate details on the identity of the dead or what prompted the airstrike. NATO was still investigating the matter, she added.

"We take all allegations of civilian casualties seriously," NATO said in a statement.

Taliban claims responsibility for car bomb

Even as U.S.-led foreign forces draw down their presence in Afghanistan, with a full exit expected by the end of 2014, the air support they provide Afghan troops in many regions is still a crucial part of operations against the Taliban, the resurgent militant movement that wants to topple the U.S.-backed Afghan government.

Past strikes that kill civilians have infuriated Afghans. Karzai has spoken out forcefully against them and banned Afghan troops from requesting NATO airstrikes during operations in residential areas.

But as the violence in Afghanistan has spread in recent years, civilians are increasingly getting caught up in it.

Around 1,000 Afghan civilians have been killed and more than 2,000 wounded in the first half of this year — a huge portion of them in insurgent attacks — according to the United Nations. That marked a 24 per cent increase in casualties compared to the same period last year.

Meanwhile, Sunday's bombing occurred in Maidan Shahr, a city in eastern Wardak province that lies just 40 kilometres from Kabul.

Hazrat Janan, a member of the Wardak provincial council said the explosion was powerful enough to shatter windows across a wide stretch of the city.

Attaullah Khogyani, a spokesman for the provincial governor, said the explosion occurred around 1 p.m. and that many of the wounded were Afghan government employees working in nearby offices. Soldiers guarding the compound managed to kill the militants on foot after the explosion, he said. He said four soldiers and five attackers died, in addition to the car bomber.

Taliban spokesman Zabiullah Mujahid claimed responsibility for the attack.