Gunmen killed seven Pakistani aid workers, six of them women, in the restive province of Khyber-Pakhtunkhwa on Tuesday, police said.
A mini-van carrying the aid workers from a local charity was ambushed in the Sher Afzal Bande area of Swabi, a town about 80 kilometres north-east of the provincial capital Peshawar, local police chief Zulfiqar Khan told dpa.
"Six women and their male colleague died at the scene," Khan said. "Their driver was critically wounded in the indiscriminate firing, whereas a child who was with his mother in the vehicle remained unhurt."
According to the police official, the unmarked vehicle was attacked shortly after it left a charity centre run by the group Support With Working Solution (SWWS).
Khan said the motive for the killings was not immediately clear.
But SWWS chief Javed Akhtar suspected that the shootings could be linked to a series of attacks in December on health workers taking part in United Nations-supported immunization campaign against polio.
"Our charity centre (in Sher Afzal Bande) is located close to a government facility offering polio immunization and it is possible that the attackers mistakenly thought our staffers were health workers," Akhtar told dpa.
His group has suspended all operations, pending the strengthening of security for staff in collaboration with regional authorities.
Since 1992, the SWWS has been working on community-based projects to improve education, health and livelihood opportunities. The aid group has partnerships with US, British and UN agencies.
Khyber-Pakhtunkhwa has seen several attacks blamed on Taliban insurgents, who have intensified their violent campaign against government targets in recent months.