A Taliban suicide car bomb killed at least 13 people, including six policemen, on Thursday in a normally peaceful region of eastern Afghanistan, officials said, nearly one month after elections.
"A suicide attacker detonated his vehicle-loaded explosive after being identified by security forces," Abdul Aziz Ghairat, police chief of Panjshir province, told AFP.
"Six police were killed, and seven civilians. A number of other civilians and security forces were also wounded."
The ministry of interior confirmed the incident at the highly-guarded checkpoint where vehicles enter the steep Panjshir valley.
"Around 5:00 pm, a suicide bomber in a Toyota Sedan vehicle detonated his explosives-loaded vehicle," it said in a statement. "As a result of this attack, six policemen were killed and a number of civilians were wounded."
The Taliban insurgents, who fight against the US-backed Kabul government, claimed responsibility for the attack via a recognised Twitter account, saying they had delivered a "heavy blow to the enemy".
Panjshir province, north of Kabul, was a bastion of anti-Taliban resistance during the extremists' 1996-2001 regime, and has been relatively stable since they were ousted.
The scenic valley in the Hindu Kush mountain range is also famous for its residents' dogged opposition to the Soviet occupation of Afghanistan in the 1980s.
The province is dominated by the Tajik ethnic group, and voted strongly in favour of Abdullah Abdullah in the April 5 presidential election.
Abdullah, who is ahead on preliminary results, was a close adviser to Ahmad Shah Massoud, the revered Tajik militia leader who was based in Panjshir and is buried at a large tomb in the valley after being assassinated in 2001.
In the last major attack in Panjshir, Afghan security forces killed six militants who stormed the provincial governor's office nearly a year ago.
Former foreign minister Abdullah and ex-World Bank economist Ashraf Ghani will compete in a head-to-head election scheduled for June 7 after results showed neither gained the 50 percent needed for first-round victory.
The eventual winner will lead Afghanistan into a new era as US-led NATO combat troops end their 13-year war against the Taliban insurgency that erupted after President Hamid Karzai took power in 2001.
Another expensive, and potentially violent, election could be avoided by negotiations in the coming weeks, but both sides have dismissed talk of a power-sharing deal.
Eight men ran in the election, with polling day hailed as a success by Afghan officials and foreign allies.
Turnout was far better than in 2009 and the Taliban failed to launch a major attack despite threats to disrupt the vote.