Clashes continued on Friday at the site of an abandoned airport project in France, despite gendarmes' claims that they had finished an operation to clear the area, reports Radio France Internationale.
Dozens of police and activists have been injured in clashes at Notre-Dame-des-Landes, near the north-west town of Nantes, this week.
There were clashes between police and protesters on Friday, with teargas being fired, barricades being erected and at least four people arrested.
Ten gendarmes were injured in an ambush on Thursday, according to police.
One was reportedly hit by acid and two by stones or Molotov cocktails.
The protesters deny the ambush claim.
Environmental protesters and farmers have occupied the Notre-Dame-des-Landes site since the previous government revived a longstanding plan to build an airport there.
Since then there have been numerous demonstrations and clashes with police in the area. After commissioning a report on the airport project last year, the government announced it would be scrapped in January.
But Prime Minister Edouard Philippe swore that the occupation would be ended, calling it a "lawless zone", and 2,500 gendarmes and bailiffs moved in this week to clear the area.
On Thursday they declared their mission accomplished but said they would remain in the area to ensure that roads were open to motorists.
The police, who claim "extremely violent, ultra-left" outsiders flocked to the site during the week, say that dozens of officers have been injured since Monday, while medical teams say 110-120 protesters have been injured.
An investigation is taking place at one farm after a rocket was fired at a police helicopter three days ago.
In a television interview on Thursday, President Emmanuel Macron said that "everything that can be evacuated has been evacuated", announcing an effective truce to "allow the legal farming projects to go ahead".