A large device exploded in a toilet in a McDonald’s bathroom in France on Thursday, according to reports.

Around 30 people were quickly evacuated from the restaurant in the town of Grenoble, where “huge flames” were seen coming out of the toilet at around noon, the Sun UK reported.

No one was injured. The blast destroyed the upstairs bathrooms.

Police said the explosion is criminal in nature.

Local media reported that someone may have lit a firecracker in the bathroom and that there are unconfirmed reports that a suspicious package was spotted there before the explosion, according to the UK’s Express.

Police have cordoned off roads surrounding the restaurant as they probe the source of the reported blast.

The country is on edge following a string of terror attacks, most recently when a man pledging allegiance to ISIS killed a police officer on the Champs-Elysees in Paris