At least 25 people, including a number of children, have been killed in an explosion in central Afghanistan, officials say.
The blast in Mohammad Agha district in Logar province happened after a truck carrying timber overturned on a road.
The vehicle blew up as the authorities were trying to remove it and clear the road, local police told the BBC.
Meanwhile, Nato says two of its soldiers have been killed in a roadside bomb attack in the south.
No further details were immediately available.
A US and UK military offensive against the Taliban is underway in the troubled southern province of Helmand.
Foreign forces have sustained heavy losses in recent days in Afghanistan, including at least seven British soldiers killed in the past week.
Logar province lies immediately to the south of Kabul and is a major centre for the Taliban insurgency.
The explosion happened on a main road from southern and eastern Afghanistan that leads into the capital, Kabul, early on Thursday.
The residents of Soark Abad village found an overturned truck with a punctured tyre and called in the police, a senior ministry of education official told the BBC.
"Two police vehicles arrived at the spot. As soon as the vehicles arrived, the truck exploded," Gen Aminullah Amarkhel said.
"The power of the explosion was so powerful that it shattered the glasses of nearby houses and scattered wood, debris and other things around. A lot of people working in the farms also got hurt."
Fifty-year-old Mohammad Sarwar, who was at the scene at the time of the blast, described the force of the explosion to the BBC.
"A loud explosion threw me several metres away. All I heard was cries and shouts of people, especially children, asking for help," Mr Sarwar said.
Gen Amarkhel said that based on the evidence about the kind of explosives in the blast, officials believed that this was a well-organised attack by insurgents.
Local police officials said that the explosives were possibly intended for an attack in Kabul.
Authorities had earlier told the BBC that it was not clear whether insurgents were responsible for the explosion.
Four of the dead were police officers but the rest were civilians including many children, police authorities in Mohammad Agha told the BBC.
The BBC's Bilal Sarwary says that the key Kabul-Gardez highway that connects Kabul with south-eastern Afghanistan passes through Logar province and Taliban and al-Qaeda militants have targeted Afghan and international forces there before.
Afghan intelligence officials believe that militants use the province to smuggle weapons and fighters in to the Afghan capital.
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