Paris (CNN)At least two people were being held hostage Tuesday in Paris, CNN affiliate BFMTV reported.
The Paris Police Prefecture told CNN that there was "a police intervention" underway in an advertising agency in the Rue des Petites-Écuries in the 10th arrondissement of the French capital. Law enforcement officials cordoned off the area.
Videos and images circulating on social media show police vehicles as well as heavily armed officers at the scene.
Authorities said that officers from a specialist unit had arrived on site in response to an "unstable person" who was holding two people.
A spokesman for the Paris police said there was no indication the incident was terrorism-related.
He declined to elaborate on the hostage-taker's motive but confirmed that someone was able to get out of the building at the start of the hostage situation.
"We are a bit worried. No one understands what is happening. ... Everyone is waiting to see what is happening," Lucie Lefrançois, who works for a communications company on the same street, told CNN.
"We don't see much; there are just lots of police."
France has been in a state of high alert following a series of terror attacks in recent years, including a knife-wielding assailant who went on a stabbing rampage last month in Paris.
Developing story -- more to come