Fire broke out at a mattress factory in Casablanca, killing at least 55 people, officials said.
Firefighters were searching the smoldering building for more bodies.
Twelve people, including a police officer, were seriously injured in the blaze, which began on the ground floor of the factory and quickly engulfed the four-story building.
About 100 of the factory's 150 employees were at the site when the fire began.
It took more than 100 firefighters more than three hours to bring it under control, the government said.
Residents said they broke down a wall to drag people from the building, most of them women and girls.
They said other people remained trapped on the upper floors and cried from the windows for help.
Onlookers said the rescue operation appeared to have been hampered by a lack of water to douse the flames.
The cause of the fire has not been determined.