Paris - Two firefighters died and nearly people 50 were injured in a massive gas explosion that gutted the ground floor of a building in a central Paris shopping district on Saturday, authorities said.
The accident occurred with Paris under security lockdown for a ninth consecutive Saturday of "yellow vest" protests, with large parts of the French capital blocked off by riot police.
"As firemen were looking for a gas leak in the building, a dramatic explosion took place," Interior Minister Christophe Castaner said, adding that one of the firemen had been buried under debris for several hours.
Castaner said on his Twitter feed that two firefighters had died, and that 10 people, including one firefighter, had serious injuries. Another 37 people had lighter injuries, he said. Earlier he had told reporters that two civilians had also died.
Just hours after the blast, thousands of yellow vest protesters marched noisily but peacefully through the Grands Boulevards shopping district of northern Paris, just a few hundred metres (yards) from the scene of the explosion.
In recent years, France has suffered a string of deadly Islamist militant attacks in Paris, Nice, Marseille and elsewhere but authorities quickly ruled out foul play.
"A this stage we can say it (the gas blast) is clearly an accident," Paris prosecutor Remi Heitz told reporters.