A car rammed into a roadblock put up by protesting farmers in southwestern France on Tuesday, killing a woman and seriously injuring her husband and teenage daughter stationed there.
The three occupants of the car that crashed into the barrier were taken into police custody on suspicion of involuntary manslaughter, police said.
But a local prosecutor, Olivier Mouysset, said that early results of the investigation suggested that the car had not rammed the barrier intentionally.
The vehicle, carrying a couple and a friend, was travelling on the road leading to the barrier despite it being closed to traffic because of the protest.
In the dark, it ran into a wall made of bales of straw at the roadblock, hit the three people and only came to a halt when it crashed into the trailer of a tractor, the prosecutor said.
A test showed that the driver, a 44-year-old man, was not under the influence of alcohol or drugs.
Simon Bertoux, the prefect of the southwestern department of Ariege where the incident occurred, told a news conference all three occupants of the car were Armenian nationals.
The broader southwestern Occitanie region has been a focal point of farmers' protests in recent days.
Farming union representatives on Monday met Prime Minister Gabriel Attal to discuss their grievances, including low food prices, rising charges for farmers, higher fuel prices and environmental protection rules that they say are unacceptable.
The woman who was killed was a member of the powerful FNSEA farmers union which has been leading nationwide protests, as are her husband and daughter.
Tensions have been running high, with the FNSEA announcing protests all this week and beyond if the government failed to respond to its demands.
FNSEA president Arnaud Rousseau first reported the incident but said no further details were available.
"In the current circumstances that farming is living through, this kind of drama is difficult to bear," he said.
A police source said that the car drove into the barrier "at speed".
The woman killed was in her 30s, her husband is in his 40s and their daughter 14.
At his meeting with the farming representatives on Monday evening, Attal promised that a number of measures would be announced by the end of the week, according to Agriculture Minister Marc Fesneau.
