The prefect of police of Paris Laurent Nuñez defends his troops.
The trade unions accused the security forces of having "targeted" their own security service in front of the Ministry of Overseas, during the October 18 demonstration for wages.
They denounced beatings "worn" by the police, "including to the head".
Seven members of the CGT had been injured.
The Ile-de-France regional unions of the CGT, FO, FSU and Solidaires unions then asked for an "investigation".
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At this time of the demonstration, a unit of police officers had been "projected on my instruction to put an end to the ongoing damage to the windows" of the ministry, writes the prefect Nuñez in a letter dated November 2.
An arrest for violence against a person holding public authority had taken place.
"It cannot be excluded that on this occasion the unit was brought into contact with members of the union order service, in the momentum of the arrest of the individual", continues the prefect. .
"Which of course I deplore, but which is perfectly consistent with my instruction to prevent troublemakers from disrupting your motorcade."
"At no time was the procession obviously targeted"
The prefect also returns to another incident: when "a radical group dressed in black" had committed damage to a BMW store.
The police had intervened to put an end to "these abuses", while the trade union procession arrived at the level of the place of the facts, recalls the prefect of police of Paris.
“At no time was the procession obviously targeted, underlines the prefect of police.
If incidents have taken place on this point, they are attributable to the urgency of the maneuver to avoid a total ransacking of the shop”.
Due to "the infiltration of very violent groups" in the processions in recent years, some "peaceful demonstrators find themselves very involuntarily close to the abuses", writes Laurent Nuñez, deploring this "interweaving" which "makes it more difficult the work of law enforcement.