In a posh neighbourhood near the Paris Saint-Germain's football ground, police found four gas canisters doused with petrol and wired to connect to a mobile phone.
French counter-terrorism investigators have arrested five suspects after a homemade explosive device was found on a usually quiet Parisian street in the early hours of Saturday.
It was discovered at dawn by a resident in the wealthy 16th arrondissement in western Paris, on rue Chanez — a short walk from the Parc des Princes football stadium where Paris Saint-Germain was playing against Bordeaux later that day.
In and outside the residential building, police found four gas canisters doused with petrol and wired to connect to a mobile phone.
Judicial sources said the bomb had failed to explode despite multiple attempts to detonate it remotely.
The suspects were still being questioned on Tuesday and several were known to intelligence services for their ties to radical Islam, a source close to the investigation told AFP news agency.
Interior Minister Gerard Collomb confirmed that one of those arrested was on a watchlist of potential Islamist militants.
Why that building?
French media quoted police as saying there was no one living in the apartment block on 31 rue Chanez who might have been considered a target for jihadists.
The Parc des Princes, a 15-minute walk away, has a capacity of close to 50,000.
Collomb suggested the motivation may simply have been to sow fear.
“Blowing up a building in a chic neighbourhood shows that no one is safe… and that it could happen anywhere in France,” the minister told France Inter radio.
“We are still in a state of war,” he said, speaking after a Sunday attack in which a man stabbed and killed two women outside Marseille’s main train station.
More than 230 people have been killed in attacks by Islamist militants in France over the past three years. The Islamic State militant group, whose bases in Syria and Iraq are being bombed by French war planes, has urged followers to attack France.
France declared a state of emergency in late 2015 after the November 13 Paris attacks, giving police special search and arrest powers.
The Assemblée Nationale, France’s lower house of parliament, on Tuesday overwhelmingly backed a bill converting many of those emergency measures into common law.
Learn more about