"Denouncing the attack in the strongest possible terms, President Ghani instructed the security institutions to investigate the incident and bring the culprits to justice, underlining that better security measures must be in place to protect staff of international organizations, particularly those delivering humanitarian assistance and services in Afghanistan," the palace said in a statement.
The incident occurred on Sunday evening when a man hurled a hand grenade on an UN-marked vehicle in Microryan-e-Chahrum in Police District 9 of the city.
The blast also wounded five civilians, including two Afghan staff members of UN Assistance Mission in Afghanistan (UNAMA).
The president also extended his deepest condolence and sympathies to the bereaved family of the UN staff and ordered the relevant authorities to spare no efforts in reaching out to those who sustained injuries, the statement noted.