The explosion, which was followed by a long gun battle, left at least 20 people dead and 50 others injured.
The incident took place at vice presidential candidate Amrullah Saleh’s office on Sunday.
The government issued a statement on Monday saying Saleh, who is the running mate of Afghan President Ashraf Ghani, had been slightly injured in the attack.
The statement added that government forces, in a six hour gun battle with the militants, had shot dead four of the assailants and saved the lives of over 150 civilians who had been caught up in the crossfire,.
The Taliban and Daesh terrorist groups are often the main perpetrators of frequent attacks of this kind in the country.
US-led foreign forces invaded Afghanistan and removed the Taliban regime, who had been ruling over the poverty-stricken country at the time, under the pretext of the global fight against terrorism in 2001.
US-led foreign troops have occupied the country ever since.
Recently, however, Washington has been negotiating with the Taliban to end the conflict.
Taliban: No direct govt. talks before foreign troops leaveThe Taliban say they will not hold direct talks with the Afghan government as long as foreign troops do not leave the country.
The exit of foreign troops from Afghanistan is a condition set by the Taliban to extend the talks.
About 20,000 foreign troops, mostly Americans, are based in the country.