On a busy road near Gare du Nord station in Paris, sandwiched between a Bengali grocery and a mobile phone shop, the green door of number 147 rue Lafayette did not stand out. There was no plaque to advertise the first-floor office of the Kurdistan information centre, where three female Kurdish activists had met on Wednesday afternoon.
As their dead bodies were removed on stretchers on Thursday morning after what French authorities described as an execution-style killing, hundreds of Kurdish people gathered to demonstrate against what they called a sinister new chapter in a decades-long dirty war.
The mysterious killings of the three activists, including Sakine Cansiz, a co-founder of the Kurdish Workers party (the PKK), have cast a shadow over peace talks between Ankara and Kurdish guerrillas.
Police found the three bodies just before 2am on Thursday in the first-floor office. According to officials at the information centre, the women had been working alone at Wednesday lunchtime. Their door was fitted with a code and buzzer system. At the end of the afternoon, one member of the community had failed to reach the women by phone. He had gone to the office but did not have a key so could not enter. Later that night others went to the office and found blood seeping under the door into the corridor.
The dead included Fidan Dogan, 28, of the Kurdistan National Congress (KNC), a European umbrella group of Kurdish organisations based in Brussels, and Leyla Soylemez, 25, a Kurdish activist in Paris. French reports said all three women had been shot in the head. Kurdish media said one woman was also shot in the abdomen. Local community members speculated that it appeared to have been a well-organised attack.
By 4am, as news of the killings spread, Kurds began to gather outside the building expressing shock and outrage. Riot police guarded the door as blinds and net curtains were closed in the first-floor windows.
Manuel Valls, the French interior minister, said at the scene that the women's "assassination" was intolerable. Police said the circumstances of and motive for the triple murder remained to be established.
The only certainty was that killings would have an impact on the tentative peace process to end the decades-long conflict between the Turkish state and the PKK, which has seen at least 45,000 deaths since the 1980s. Turkish officials are holding talks with Abdullah Öcalan, the PKK leader jailed on the prison island of Imrali, to end the dispute.
In the past Kurdish groups have suffered violent internal conflict as well as being targeted in extrajudicial killings by Turkish nationalists, often linked to the military or the so-called "deep state".
The Turkish prime minister, Tayyip Erdogan, said it was too early to apportion blame. "This may be an internal reckoning. Aside from this, we are engaged in a struggle against terrorism … but there are people who don't want this. This could be a provocative undertaking by these people," he said during a visit to Senegal.
Remzi Kartal, a KNC leader, told Reuters: "This is a political crime, there is no doubt about it.Öcalan and the Turkish government have started a peace process, they want to engage in dialogue but there are parties that are against resolving the Kurdish question and want to sabotage the peace process."
Kurds in Turkey said the murders could be part of efforts to derail peace talks. Mehmet Ali Ertas, an activist and journalist at the pro-Kurdish news agency DIHA in Diyarbakir, said: "These murders happened during a pivotal moment. Military operations [against the PKK] and the talks [with Öcalan] are both ongoing. It looks like someone is trying to impede on the possibility of a peace process, like someone wants to create chaos."
Ihsan Kaçar, head of the Istanbul Human Rights Association, said the killings could have been an attempt to undermine positive reaction in Turkey to the nascent peace process. "I was very hopeful about the talks with Öcalan, but after reading about the killings in Paris, these hopes have been shattered."
Many commentators warned against premature conclusions, urging the French and Turkish governments to solve the murders as quickly as possible to prevent a backlash. "It is too early to speculate about the reasons for the killing," Vahap Coskun, assistant professor at Diyarbakir Dicle University, said. "The most important thing now is for Turkey to fully co-operate with the French authorities in order to investigate the murders, and to disclose the results to the public."
In Paris 200 Kurdish protesters led a rally from the building where the women were found, carrying flags of Öcalan and shouting: "We are all the PKK".
One 25-year-old protester, who said his parents were political activists, described a community in shock. He said: "There are so many Kurdish political refugees in France. If we can't feel safe here, where can we feel safe?"