Afkham slammed the atrocity and condoled with the bereaved families of the victims and the Pakistani people and government.
"Extremism and terrorism are against humanity and Islam, and killing innocent people, with any purpose and in any form, is rejected and unjustifiable," she said.
The objective of such terrorist attacks is to undermine unity in Pakistan, Afkham warned, but expressed confidence that prudence and rapport between the Pakistani government and nation would safeguard stability and security in Iran's neighboring country.
Earlier on Wednesday, at least 43 people were killed and many more wounded in an attack on a bus carrying a group of Shiite Muslims in Karachi.
Local officials say the attack was carried out by six gunmen, who approached the bus on three motorcycles.
Targeted killings against Shiite Muslims in Pakistan have drawn international outrage, with rights groups and regional countries expressing concern over the growing violence.
Shiites are seen as a minority group in Pakistan. They make up about a fifth of the country's population of over 180 million.