A bus is engulfed in flames in central Paris, with thick clouds of black smoke billowing into the sky, witnesses and local officials say. Only a few details are currently available.

The incident began on late Monday afternoon when a RATP public transportation bus caught fire at Place Maubert and Saint-Germain Boulevard, close to the Notre Dame Cathedral.

“Bus fire with heavy smoke in Place Maubert,” French police said in a tweet. “The emergency services are responding, avoid the area.”

The cause of the fire was not immediately known, but footage from the scene showed the entire vehicle engulfed in flames. Several loud bangs were heard.

It’s unknown if anyone was injured.