BEIRUT—At least one hundred people today have died and hundreds more were injured in the massive explosion in Lebanon’s funds, the Red Cross explained Wednesday, as the military cordoned off locations worst affected by a blast that caused widespread injury and blanketed Beirut in dust and debris.

Beirut was strike by a strong explosion at a warehouse in the city’s port Tuesday night, which appeared to have been activated by a fireplace. The warehouse held really explosive substance that Lebanese officers determined as ammonium nitrate.