Deputy police chief Asadullah Shujaye said the attacker could have caused much greater harm if he had reached a crowded market nearby. The bomb that went off today was concealed in a motorised rickshaw.
Shujaye said the bomber was likely from the Taliban, but the insurgents have not taken responsibility.
The Taliban have a large presence in Ghazni, which is on transit routes linking the capital, Kabul, to the southern city of Kandahar and the eastern border with Pakistan.