PARIS - The three Kurdish women were slain, two with bullets to the head, the third with a shot to the stomach. It was a carefully planned killing in a nondescript building in central Paris.

When the bodies were found early Thursday, the office was locked from the outside. Three bullet casings were found on the floor. Blood was splattered on the door.

News reports identified one of the women as Sakine Cansiz, a founder of the Kurdistan Workers' Party, known by the initials PKK. Another was Fidan Dogan, the head of the institute and a representative of the Kurdistan National Committee. The third woman was Leyla Soylemez, a youthful Kurdish activist.

There were competing theories over who might be responsible, and outraged Kurds poured into the street in Paris, blaming Turkey. Officials there said the killings were likely a dispute among Kurds, perhaps intended to derail new peace talks between the government and the PKK's jailed leader, or to settle a score.

But these were theories. The evidence spoke only to a well-planned job.

Interior Minister Manuel Valls said the killings were "without doubt an execution."

The bodies were found around 2 a.m. inside the Kurdish Information Center, which is used to promote Kurds' political and cultural agendas. Someone would have to have known the office was there; there was no plaque outside. And the front door could only be opened with a digital code -- or a person could be buzzed in by someone already inside, said center manager Leon Edart.

The anti-terror unit of the prosecutor's office will oversee the investigation, said spokeswoman Agnes Thibault-Lecuivre.