The attack, claimed by Daesh, took place in eastern Nangarhar province's Kama district where supporters of independent candidate Abdul Naser Mohmand had gathered to back his campaign in parliamentary elections scheduled for October 20.
A suicide bomber blew himself up at an election rally in Afghanistan's eastern province of Nangarhar on Tuesday, killing at least 13 people and wounding more than 30, officials said, warning the toll was likely to climb.
The attack took place in the province's Kama district on Tuesday afternoon where supporters of Abdul Naser Mohmand had gathered to back his campaign as an independent candidate in Afghanistan's parliamentary elections scheduled for October 20.
Attaullah Khogyani, spokesman of the provincial governor, said at least 13 bodies were taken to hospitals, but others said the toll was likely to be higher.
"Elders were speaking at the meeting when there was suddenly a huge blast," said Sayed Humayoun, who was attending the meeting in Kama district, outside the provincial capital Jalalabad.
"I was knocked unconscious but when I opened my eyes there were bodies scattered all around the blast area," he said, adding that he could see dozens of dead and wounded bodies on the ground.
Resident of the area, Abdul Rahimzai, said, "We want the government to provide security for the campaigning of candidates. I also ask that parliamentary candidates that when you are not able to ensure security for your gatherings, don't hold them, as it results in killing of our innocent people."
Daesh claims responsibility
Daesh claimed responsibility for attack, Reuters reported, citing the group's Amaq news agency.
Militant group Daesh has claimed a series of attacks this year that have killed scores of people in Nangarhar, on the border with Pakistan.
The parliamentary election is seen as both a dry run for the more important presidential election next year, and a test of the government's ability to provide security.
Officials acknowledge that sustained violence could delay the process if it proved unsafe for voters to go to polling stations.
Turkey condemns 'heinous terrorist attack'
Meanwhile, Turkey condemned the deadly attack, saying "We learned with sorrow that the terrorist attack that targeted an election rally today in Nangarhar province of Afghanistan resulted in many loss of lives and injuries."
"We condemn this heinous terrorist attack and wish Allah's mercy upon those who lost their lives, speedy recovery to the wounded, and convey our condolences to the friendly government and the brotherly people of Afghanistan," Turkish foreign ministry said in a statement.