The blast happened in Khan Abad district, Kunduz province, at around 6:00 pm (1330 GMT) yesterday. Local officials initially said six people were killed and 22 others were wounded.
But in a fresh statement today, the Afghan interior ministry said: "Ten people were killed including a police soldier and 24 others were wounded including 18 men, five women and a police member." The explosives were planted in a bicycle near an ice-cream shop, the statement added.
Police have launched an investigation into the blast, which local officials blamed on the Taliban.
Militants have frequently targeted the Afghan police and other government employees in their near decade-long insurgency.
But civilians are the biggest casualties in the war, with 2,777 killed last year, according to the United Nations.
The north of Afghanistan is usually more stable than the volatile south and east but has seen an upsurge of violence in recent times.