By John Irish and Johanna Decorse
PARIS/TOULOUSE (Reuters) - Three men suspected of joining Islamist militants in Syria gave themselves in to French authorities on Wednesday after a day of high confusion which exposed security shortcomings in France, including poor collaboration with NATO ally Turkey.
Officials wrongly claimed on Tuesday the three French nationals - who include the brother-in-law of a gunman who killed seven people in France in 2012 - had already been arrested before admitting they were still at large.
The lawyer for Gael Maurize, one of the men, said they had handed themselves in at a village police station after driving some 170 km (105 miles) northwest of Marseille airport where they had landed. Authorities had been waiting for them in Paris.
"The three men handed themselves in because they want to be listened to by the authorities," lawyer Apollinaire Legros-Gimbert told Reuters, adding the men had been in touch with French authorities for several months before their return.
"They were stunned not to have been questioned yesterday."
Embarrassingly for the government, the case has come at a time when France is already on high security alert after militant group Islamic State threatened French targets. France has joined a U.S.-led campaign of air strikes, hitting Islamic State targets in Iraq last week.
The government has also been lobbying lawmakers to adopt tougher anti-terrorism legislation to prevent French citizens joining militants abroad. Paris fears returning French fighters, radicalised by their experiences in the Middle East, could plot attacks on their home turf.
Defense Minister Jean-Yves Le Drian tried to push some of the blame for the confusion over the men's fate onto Turkey.
"There was obviously a lot of confusion, but it's largely down to difficulties and lack of very good collaboration with the Turkish services," he told France Info radio on Wednesday.
"This confusion shows we have to strengthen our relations, the methods and the actions with the Turkish authorities."
Asked about the case, a Turkish foreign ministry official said: "Turkey has done what needed to be done on this matter."
Thousands of volunteers from France and other Western countries have traveled to Syria and Iraq, often via Turkey, to join Islamist fighters, including Islamic State which now controls large swathes of Syrian and Iraqi territory.
Turkish authorities put the three men on a plane bound for Marseille on Tuesday after the pilot of an earlier flight to Paris had refused to let them board because they lacked necessary documents.
Compounding the confusion, the French Interior Ministry then said they had been arrested on arrival in Paris and had been charged with being linked to a terrorist organization.
It later admitted this was not the case and said the French intelligence services had only been informed of their arrival after they had entered France at Marseille without checks.
"The Turkish initiative to change the plane was unfortunate," Le Drian said, adding the passport control system in Marseille had not been working, as is "often the case".
Politicians from the far-right National Front to the Green Party decried what they called the government's incompetence.
"The non-arrest of the three suspected jihadis from Turkey illustrates the extraordinary amateurism of the government," the National Front said in a statement.
French Interior Minister Bernard Cazeneuve said he had ordered an investigation of the case and said he would also travel shortly to Turkey to ensure the errors were not repeated.
An interior ministry official said the three men had long been under surveillance by security services. One of them, Imad Jebali, has already spent time in a French prison after being charged for links to a jihadist network in Iraq in 2007.
Another of the three, Abdelwaheb al Baghdadi, is the brother-in-law of Mohamed Merah, who killed seven people including three Jewish children in southwest France in March 2012 before being shot dead by police.
Christian Etelin, a lawyer advising Baghdadi's wife, told Reuters on Tuesday the men had originally gone to Syria to live in a religious society. They had escaped Islamic State to hand themselves over to Turkish officials because they had been terrified by the "fanaticism" there, he said.
Diplomats and officials in Turkey say intelligence is not being sufficiently utilized to prevent foreign nationals traveling to join militants in Syria and Iraq.
Security experts said French police officers based in Turkey should have been coordinating Tuesday's handover of the men.
"It's impossible to understand how we could have missed three jihadis when there is a major terrorism threat," said Eric Denece, Director of French Center for Research on Intelligence.
(Editing by Gareth Jones)