The French Interior Minister Gerald Darmanin said that the French police are carrying out an operation in the area of the attack, noting that a crisis cell meeting is being held in the Ministry of the Interior to follow up on the incident.
The French police called, via Twitter, on citizens to stay away from Notre Dame Church in the city of Nice, in the south of the country.
Christian Estrosi, mayor of Nice, France, said on Twitter that he believed the attack near the church in Nice was a terrorist attack.
Estrosi confirmed that one person had been arrested after the attack.
In turn, the French far-right politician Marine Le Pen told reporters at Parliament in Paris that a "beheading" occurred during the attack.
French police said that "a man armed with a knife attacked a number of people at nine o'clock on Thursday morning in Notre Dame Cathedral in Nice in southern France."
This incident comes in the context of a major security alert in France, after a professor was beheaded near Paris earlier this month.