Thomson ReutersPARIS (Reuters) - French police have detained a Syrian asylum seeker in connection with the Normandy church attack, two sources said on Friday, as security services widened their investigation into the killing of an elderly priest at the altar by two would-be jihadists. Three days after teenagers Adel Kermiche and Abdel-Malik Nabir Petitjean chanted in Arabic as they slit the throat of Father Jacques Hamel, investigators are probing their network of associates from the northern Normandy region to the alpine east. A police source said the Syrian man was arrested near a refugee center in the rural Allier region of central France, where Petitjean lived for four years with his parents until 2012, according to French media. A copy of the Syrian's passport was found at Kermiche's family home, the police source said. A judicial source confirmed a Syrian was being held in custody.