At least seven people were killed and many wounded in a suicide bomb blast that in the Afghan capital on Thursday near a gathering of supporters of regional leader Atta Mohammad Noor, according to the interior ministry.
Noor is the governor of the northern province of Balkh and a leader of the mainly ethnic Tajik Jamiat-i-Islami party.
The explosion was the latest in a wave of violence in Afghanistan that has killed and wounded thousands of civilians this year.
Political tensions are up as politicians have begun jockeying for position ahead of presidential elections expected in 2019.
A spokesman for the interior ministry said the suicide bomber approached a hotel hosting the gathering in the Khair Khana district of Kabul, on foot. The dead included five policemen and two civilians, and many more were wounded.
President Ashraf Ghani on Wednesday sacked the chairman of the Independent Election Commission, raising doubts over whether parliamentary and council ballots scheduled for next year will take place as planned.