The bomb blast in Samangan province tore through a bus, killing at least 11 people, according to Afghan officials on Sunday.
Among the victims were three female election workers and at least two observers from the campaign of presidential candidate Abdullah Abdullah. They were returning from a polling station in Aybak, the capital of Samangan province, after voting had ended on Saturday.
"The attack killed eleven people," the governor of Samangan, Khairullah Anosh, told the AFP news agency. "The election workers had finished their job and were heading home."
In a separate incident, the Taliban cut off the fingers of 11 people in the western province of Herat to punish them for voting, according to police spokesman Raoud Ahamdi.
There were 150 reported incidents of violence during voting on Saturday. Afghanistan's Defense Ministry put the death toll at 227 people. The dead include 33 civilians, 18 soldiers and 176 Taliban fighters, according to ministry spokesman Zahir Azimi. The Taliban had threatened "non-stop" assaults against polling stations.
Initial estimates suggest that 7 million Afghans turned out to vote in the presidential runoff, according to Independent Election Commission Chairman Ahmad Yousuf Nouristani. That's nearly 60 percent of Afghanistan's 12 million registered voters.
In the first round of voting, former Foreign Minister Abdullah Abdullah garnered 45 percent of the vote compared to ex-World Bank official Ashraf Ghani's 31 percent.
Collecting and counting the ballots is expected to take more than a month. Preliminary results are expected on July 2 with final results scheduled to be announced on July 22.
slk/kms (AP, AFP, dpa)