Local officials sent in the Forest Vigilance Platoon PVF, consisting of 15 reservist gendarmes, a senior police officer and two motorcyclists from the mobile brigade, backed up by the helicopter.
The PVF patrol the forest on motorbikes, all-terrain bicycles or in cars, where possible, on the hunt for fire-starters, despite the fact they are spread across three zones.
The PVF will free firefighters who have been stretched thin battling blazes that since Tuesday have burned up 7,400 hectares of pine forests at the southern end of Gironde, set up just last week.
After the major fires in July, we observed a rise in the number of arson cases, said Martin Guespereau, deputy prefect for defence and security in the Nouvelle-Aquitaine region.
There are around twenty fires of unknown origin a day in Gironde. According to the National Forests Office, nine out of 10 fires were started by people and three out of 10 were deliberately started, according to France's National Forests Office.
Captain Christophe Roque, who was assigned the task of bringing the team together, said that the Forest Vigilance Platoon is a support division whose aim is to prevent, detect and possible to arrest.
Red- and-white signs at the edge of Soulac-sur- Mer forest inform walkers that the forest is off-limits to the public until further notice - and has been since Aug 11.
A number of cyclists were out on the trails on Saturday, but were quickly intercepted by the gendarmes of the PVF.
One member of the team, Bruno Kechtoff, said that as soon as we come across someone, we get their identity. If we come across the same person several times, that becomes suspicious. Two outbreaks of fire barely 500 m apart, near Bazas, south of Bordeaux, the regional capital, come over the radio. A local reported seeing someone wearing yellow-trimmed trousers. The LVF's helicopter veers off towards Bazas, 130 km away.
Constable Jeremy Hernandez says where they are sent next depends on where the next fires are going to break out. We have been called here urgently but we can move if other areas are concerned. They are then in their car and drive off, siren wailing, on the look-out for a quad reported in the woods.