"Seven civilians, including three children and one woman, were killed and 17 wounded," Assadullah Safi, deputy provincial police chief, told AFP.
Baz Mohammad Emat, the director of Ghazni central hospital, said that some of the wounded people were in a critical condition.
There was no immediate claim of responsibility for the attack, but roadside bombs are the weapon of choice for the Taliban.
Tens of thousands of civilians have been killed both by insurgents and NATO and Afghan forces since the Taliban launched an insurgency in 2001 after being deposed in a US-led invasion.
Afghan officials said that a NATO air strike last Saturday killed at least 16 civilians in eastern Kunar province.
NATO denied any civilians were killed and said 10 militants had died in the attack.