Students at two schools in the Bordeaux region of France were forced to leave class under police protection after anonymous calls reportedly threatening a bomb attack.
The calls were received by the Lycee de la Mer and Lycee Saint Famille Saintonge schools at around 11am on Monday morning, report France Info.
The calls are believed to have made references to an explosive device.
At least 20 armed police responded to the incident, and a security sweep was “triggered without delay”, an Aquitaine government press release said.
A security perimeter remains in place around the two schools, one of which is located in the center of Bordeaux and the other in the coastal town of Gujan Mestras, near the Bay of Biscay.
An investigation to determine if the threat is credible is expected to last until the afternoon.
France remains on a high alert following a series of terrorist attacks perpetrated by Islamic extremists.
One week after the Nice truck attack on July 14, which claimed the lives of 86 people, the French parliament elected to extend a state of emergency by six months.
READ MORE: Islamic State claims responsibility for truck attack in Nice
“With a new terror threat looming, as the Nice attack starkly highlights, this will enable the security services to take swift, effect action to dismantle networks, place individuals under surveillance and prevent acts from being committed,” a government spokesperson said.