Reports of several horrifying attacks in France's capital began surfacing on Friday evening: In addition to news of a reported shooting in Paris at the restaurant Le Petit Cambodge in the 11th arrondissement and civilians reportedly being taken hostage at Paris' Bataclan Theatre, there have also been reports of three explosions at Paris' Stade de France, and a dismembered body also reportedly being found near the stadium. Earlier Friday, a friendly France-Germany football match was taking place at the Stade de France, with French president Francoise Hollande in attendance. It was during this game that an explosion went off — and, per video feed of the match, the explosion could be heard mid-match from the Stade de France.
Though it's not known if spectators were immediately aware of what exactly the loud noise was during the game — it's likely some may have not even been aware of the surrounding violence until later due to poor cell service in the stadium — the sound from the explosion is still very clearly audible, even in the video feed of the game.
According to The Telegraph , the sound heard comes from grenades thrown by the attackers:
Grenades were reportedly thrown at a stadium in the north of the French capital where a football match between France and Germany was being held, witnesses said.
Though details are scarce and still quickly developing, according to France 24, officials reportedly believe these attacks are connected, and 60 casualties have been reported. When the explosions reportedly took place, President Hollande was evacuated from the stadium — his current whereabouts are not known. Others viewing the match were sealed inside the stadium by police, and they eventually moved onto the field, as chaotic and harrowing images and video from the scene illustrated.