French anti-terrorist police detained six people yesterday as part of an investigation into networks recruiting Islamic militants to fight in Iraq, judicial sources said. Police from the DST domestic intelligence agency also searched a number of premises under warrants issued by three leading anti-terrorist judges. The suspects can be held for four days after which they must be brought before a magistrate or released.Since late 2004 French anti-terrorism officials have become increasingly concerned at the number of its nationals travelling to Iraq via Syria to fight international troops supporting the US-installed government. In January and April of this year, police smashed two recruitment rings. Six people remain in prison pending further investigation. In late June, a Moroccan was arrested on his return to France from Syria as part of the same investigation into recruitment networks. Police said he was in possession of material that could have helped make a bomb.