Three people are now confirmed dead – including one woman who was "decapitated" – following a terror attack in the French city of Nice, the mayor Christian Estrosi has said.

“It seems that, according to the first findings of the police, the woman who was inside the church has been decapitated. For the other victims, we cannot say anything at the moment,” he told BFM TV.

France's anti-terror prosecutor has taken on the investigation into the knife attack in Nice, a spokesperson for the prosecutor's office said.

The knife attack took place in the vicinity of the city's main church, the Notre Dame Basilica.

French President Emmanuel Macron will travel to Nice on Thursday after participating in a crisis meeting at the Interior Ministry, the Elysee Palace has said.

The country's Prime Minister Jean Castex led lawmakers in a moment of silence at the National Assembly on Thursday morning after news of the incident broke.

The mayor of Nice, Christian Estrosi, wrote on Twitter that he has spoken with Macron over the phone this morning, adding that the President passed on his thanks to local police.