At least three voters were wounded Saturday morning in a blast at a polling center in eastern Afghanistan's province of Logar, a district governor said.
It was the first attack against voters in the country's presidential elections.
"An improvised explosive device (IED) went off near a polling center in Mughul area of Mohammad Agha district at around 9:30 a.m. (local time), leaving three voters injured," governor Abdul Hamid told Xinhua.
The injured were shifted to a district hospital in the province, 60 km south of Afghan capital Kabul.
Earlier on Saturday, Afghans began voting to elect a new president for the next five years in the first transfer of power through polling in the country's history.
The voting resumed in the area and there is no threat at the site, the official added.
In neighboring Ghazni province, three rockets fired by militants landed in suburb of the provincial capital Ghazni city, causing no casualties.
"Based on reports by our police forces, no major security incident took place during the election process as of now across the country to deter people for voting," Afghan Interior Minister Mohammad Omar Daudzai said in a statement issued at around 10:36 at the morning.
The voters will also cast vote for the provincial councils candidates at the same day.
More than 12 million eligible voters, 35 percent of them women, are expected to cast their ballots in the one-day election across the war-torn country.
The polling stations opened at 7:00 a.m. (local time) Saturday and will close at 4:00 p.m. in the afternoon.