The bodies of the women, including Sakine Cansiz, a co-founder of the Kurdistan Workers Party, were found early Thursday at the Kurdistan Information Center in Paris, Today's Zaman reported.
All the women had been shot.
Speaking to reporters, Prime Minister Recep Tayyip Erdogan said the women may have known the person who killed them. A sophisticated lock on the buildings would have kept out intruders, suggesting the door was opened to someone the women knew.
Erdogan said it was a strong possibility the homicides were done by someone inside the PKK, raising the possibility of a split within the organization.
Turkey is negotiating with the PKK to end a 28-year civil conflict, and the prime minister said some people in the organization may not want peace.
French Interior Minister Manuel Valls has described the killings as "surely an execution."