Two firefighters and a woman visiting from Spain were killed when a powerful gas explosion ripped through a building in central Paris on Saturday.

The 9 a.m. blast, which was deemed accidental, also injured 47 people, 10 seriously, according to the Paris prosecutor’s office.

The explosion hit in a city on edge as the latest “yellow vest” anti-government demonstrations were taking place. The protests have frequently degenerated into violence and vandalism.

It took place in a part of the city home to restaurants and tourist attractions, including the Musee Grevin wax museum and the popular Rue des Martyrs.

Firefighters had responded to the building, which hosts a bakery and restaurant on the ground floor, to investigate a reported gas leak when it exploded. The shock wave was felt blocks away.