Were French police target of terror plot? Security is upped at Paris HQ as attack clues mount

Police upped security at the headquarters of France’s criminal investigations police Wednesday as investigators who were questioning five suspects in an alleged terror plot sought to identify their potential targets from a seized mobile telephone, officials said.

A police official confirmed that security was reinforced at the imposing judicial police headquarters on the Seine River, known by its address, 36 Quai des Orfevres. The building reportedly showed up, along with others, in searches performed on a telephone belonging to one of the suspects.

Investigators are concentrating on uncovering clues to what authorities say was a thwarted effort to launch another attrack in France, two officials with knowledge of the case said. The suspects must be issued preliminary charges on Thursday or released.

Two suspects — one of them a school employee — apparently travelled briefly to Syria, the two officials said, increasing suspicion of a link to Islamic extremists. The officials were not authorized to discuss the case and spoke on condition of anonymity.

Seven people originally were arrested early Sunday in Strasbourg, in eastern France, and in Marseille, in the south, but two of them have been released.

A telephone belonging to one of four men arrested in Strasbourg and possibly computers seized in the investigation have revealed the devices were used to search for locations, including for an amusement park, that might have been potential attack targets, the officials said.