Police shut down part of central Paris in a huge counter-terror operation after a "false alarm" on Saturday afternoon.
Part of the Les Halles and Châtelet areas were cordoned off by armed officers as security operations continued, with members of the public and tourists warned to stay away from the French capital's 1st Arrondissement.
Police said the operation was concluded by 4.50pm (3.50pm BST), saying there was "no danger to report", and officials later confirmed the incident was a false alert.
A hostage situation was initially feared to be underway after witnesses reported hearing gunshots near the Saint Leu Saint Gilles church, sparking panic before the arrival of "massive" numbers of security forces.
The French government's "SAIP" public warning system sent out an electronic notification reading "church attack alert" at 4.30pm local time (3.30pm BST) but gave no further information.
Bernard Cazeneuve, the interior minister, said a "false alarm" sparked the intervention at the church in Rue Saint Denis, under two months after Isis supporters murdered a Catholic priest in Normandy.
"The circumstances that led to this intervention have not yet been precisely detemined," a statement said.
"As a precaution, the SAIP alart system was immediately activated. The minister welcomed the quick response by security forces and their great professionalism in all circumstances serving the safety of the French people."
France remains on high alert following a series of stabbings and attacks that have killed more than 230 people since January 2015, with police powers intensified by a continuing state of emergency.
Three women were arrested earlier this month on suspicion of planning a terror attack directed by Isis commanders in Syria.
Authorities said the trio had been preparing to drive a car laden with gas cylinders into a major railway station.
The country has been rocked by a series of terror attacks starting with the massacres at Charlie Hebdo’s offices and a Kosher supermarket in January last year and the Paris attacks.
An Isis supporter driving a lorry killed 86 people celebrating Bastille Day in Nice and two teenage jihadists killed a Catholic priest after storming a church in Normandy weeks later.
The assaults have increased pressure on the French security services while reigniting national debates on immigration, integration and secularism.
