MARSEILLE, FRANCE // France has bannned some paratroopers from wearing uniforms in public after three were shot dead in southern France, possibly related to the killed of 16 civilians by a US soldier in Afghanistan.
Four French soldiers were also shot dead by an Afghan colleague in Afghanistan this month after US soldiers burnt Qurans. The backlash over the burnings has so far killed dozens of Afghans in protests, while six US soldiers were killed by their Afghan colleagues.
The heightened security in southwestern France follows the killings in Toulouse last Sunday and Montauban on Thursday of three north African French soldiers thought to have been carried out by the same man.
Prosecutors confirmed the same calibre of weapon, and probably the same gun - an automatic pistol - was used each time.
All three soldiers killed - one in Toulouse and two in Montauban - were French citizens of Maghrebin backgrounds. A comrade who was critically wounded in the Montauban shooting is French Caribbean.
Michael Valet, the public prosecutor for Toulouse, said one of the four had served in Afghanistan and another in Africa. The others served mostly in France. There appeared to be no link between the four.
The men's ethnic origins mean police are considering racism.
When this theory was put to Mr Valet, he replied: "They are all good citizens of France."
French military forces have been deployed in Afghanistan since 2001. The country has become accustomed to the deaths of soldiers there and public opinion, as in the UK, wants the troops home.
At the end of 2009, there were 4,000 French service personnel in Afghanistan.
The president, Nicolas Sarkozy, has promised to reduce that to 1,000 by the end of this year and François Hollande, his socialist opponent in the presidential election, said he would withdraw all forces in the same timescale.
In Montauban, the killer fired as the three members of the 17th Parachute Engineering Regiment withdrew money from a cash machine.He turned one victim over and shot him again, showing no interest in the money.
In Toulouse, 46 kilometres south of Montauban, the killing bore several similarities. A 30-year-old non-commissioned officer in the 1st Parachute Logistics Regiment and named as Imad Ibn Ziaten, was shot in the head in a car park outside a gym.
Unlike the men shot four days later, he was in civilian clothes. However, he had advertised a motorbike for sale on the internet, identifying himself as a soldier.
The garrison town of Montaubanis in shock.
"It was clearly soldiers the killer was after," said a baker's shop assistant, identified by Le Figaro newspaper as Laura.
"A pensioner waiting behind them to withdraw money was pushed aside by him."
* Additional reporting by Agence France-Presse