A young French woman was detained by police in Paris Monday as part of an investigation into underground groups allegedly recruiting volunteers to fight against US troops in Iraq. The 18-year-old woman, who has not been named, is believed to have been the girlfriend of a man who left to join the insurgency and was killed. Last month six men were arrested in the Paris suburbs as part of the same investigation, and all were released after the maximum four days of questioning allowed by French law. Intelligence services have identified about 20 men who have been recruited in France for the Iraqi insurgency, of whom six are believed to have died in combat or suicide attacks.