At least 37 people have been injured, four of whom are in a critical condition, after a gas explosion sparked a blaze in buildings in the Latin Quarter of Paris. The blast happened in the fifth arrondissement at about 5pm on Wednesday and resulted in several buildings catching fire, local officials said. Police said many of the injured were hit by the force of the blast and by debris. Rescue workers were looking for two people in the rubble on Wednesday night, according to Gérald Darmanin, the interior minister. Police told people to avoid the Val-de-Grâce area, near the Pantheon and Luxembourg Gardens, after the facade of a building collapsed and the fire appeared to have spread to neighbouring buildings. Laurent Nuñez, the Paris police chief, said the explosion happened at 277 Rue Saint-Jacques inside a building that included the Paris American academy, a bilingual school of fashion and design. Local people described one powerful explosion and a smaller one. One man told France Info public radio: “It was shocking. It’s a disaster.” Alexandra, a local pharmacist, said: “We heard an incredible, very loud explosion at around 5pm, we felt the force of it. We thought this isn’t a storm, this is serious. We heard the fire services. I went out to see if I could help. But it’s all shut off. There are large numbers of fire services and emergency services. It’s atrocious.” Some reported a huge plume of smoke rising above the neighbourhood. Olivier Galzi, a journalist who was nearby at the time of explosion, told BFM TV that he had seen the facade of a nearby building collapse. Police, fire crew and ambulance services were at the scene. Some 70 fire trucks and 270 firefighters battled the blaze. The Paris prosecutor said an investigation was opened into aggravated involuntary injury and the inquiry would examine whether the explosion stemmed from a suspected violation of safety rules. Prosecutor Laure Beccuau said investigators would seek to “determine whether or not there was failure to respect a rule or individual imprudence that led to the explosion”. At about 6.45pm local time, police said the fire was under control and that rescue work was continuing. Rue Saint-Jacques leads from the Notre-Dame to the Sorbonne University and the Val-de-Grâce military hospital and is a few blocks from the popular Jardin du Luxembourg. The area is usually packed with tourists and foreign students in the early summer. “I was at home writing … I thought it was a bomb,” Monique Mosser, an art historian, told Reuters, adding that many of the windows in her building had been blown out by the blast’s shockwave. “A neighbour knocked on the door and told me that the fire brigade were asking us to evacuate as quickly as possible. I grabbed my laptop, my phone. I didn’t even think to get my medication.” Alexis, a 23-year-old student living across from the building, told AFP he heard “a huge bang”, and then his windows were blown out. “It was super scary, there was smoke, and debris, and leaves flying,” he said. “We didn’t know if it was a terrorist attack.” Renowned Greek-French filmmaker Costa-Gavras was among the witnesses at the scene. “A huge noise and the house was shaken like this,” said the 90-year-old, visibly rattled. “We thought, what is going on? We thought it could be the sky ... It’s not something to laugh about.”