SWABI, Pakistan — Hundreds of Pakistani villagers have turned out for the funerals of aid workers and teachers who were gunned down by militants in the country's northwest.

Family and friends on Wednesday buried two of the female teachers, along with a female health worker and a male medical technician.

The four were among seven people killed Tuesday on their way home from a community center in the town of Swabi where they were employed by a nongovernmental organization (NGO).

There has been no claim of responsibility, and no arrests have been made.

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.

Many militants in Pakistan view the vaccination campaigns as cover for western espionage.