Zakir Hussain, head of an education wing of Al Khidmat Foundation, and his driver were shot dead by two unidentified gunmen while driving to a school run by the charity near Charsadda city of Khyber-Pakhtunkhwa province.
The gunmen escaped on a motorcycle after the attack, police officials said.
The Pakhtunkhwa Civil Society Network, an alliance of NGOs, demanded the attackers be arrested.
"We strongly condemn the attack on Al Khidmat Foundation vehicle and killing of its workers and demand arrest of the attackers," PCSN said in a statement.
In a separate incident in Dera Ismail Khan, unidentified gunmen shot and killed two persons and injured three more at a hotel.
Police cordoned off the area and conducted a search.
On Tuesday, seven charity workers, including six women, working for a Pakistani charity were shot dead in Swabi district of Khyber-Pakhtunkhwa.
