The seven had worked at a community centre in the town of Swabi that included a primary school and a medical clinic that vaccinated children against polio.
Some militants oppose the vaccination campaigns, accusing health workers of acting as spies for the US and alleging the vaccine is intended to make Muslim children sterile.
As mourners carried the coffins through the town for burial, family and friends expressed horror that such an attack had struck their community.
"I told her many times at home 'be careful as we are poor people and take care of yourself all the time,'" said Fazal Dad, whose daughter was among the seven killed.
"And always in response she said: 'Father, if I am not guilty, no one can harm me.'"
The group was on their way home from the community centre where they were employed by a non-governmental organisation when their vehicle was attacked on Tuesday.
The four militants on motorcycles spared the young son of one of the women who was riding in the van, pulling him from the vehicle before spraying it with bullets.
The driver survived and was being treated at a Peshawar hospital.
There has been no claim of responsibility, and police have not made any arrests.
The director of the NGO said he suspected the attack might have been retribution for the group's work helping vaccinate Pakistani children against polio.
Swabi: Hundreds of villagers in northwest Pakistan turned out on Wednesday to bury five female teachers and two health workers who were gunned down a day earlier by militants in what may have been the latest in a series of attacks targeting anti-polio efforts in the country.
First Published: Thursday, January 03, 2013, 08:30