Clouds of thick, black smoke billowed over the Vatican Thursday following a fire that broke out in a neighboring district, according to reports.

Worried residents tweeted pictures of the heavy plumes of smoke appearing to cover the pope’s city in Rome, the Sun reported.

Witnesses initially reported that the fire originated at the Vatican and that there was a “loud boom” accompanying the smoke.

But local media reported that the fire broke out at a “car warehouse” in the Battistini district in Rome, the Sun said.