Heavy rains have flooded an underground clandestine textile factory in the northern Moroccan city of Tangier, killing at 28 people.

The deceased were submerged during torrential rainfall on Monday as flood waters reached 3 metres deep, Morocco’s state news agency, MAP, reported.

Firefighters have so far rescued 18 workers from the flooded factory in a villa basement and moved them to a hospital.  

Emergency workers are still searching for more people trapped inside. 

Authorities said they had launched an investigation, as the total number of workers of the illegal factory remains unclear.  

Local media reports indicate that the victims may have died after the electrics in the house short-circuited, but authorities have not yet confirmed.

Informal labor accounts for 14% of Morocco’s gross domestic product, and about a fifth of non-agricultural economic activity, according to a recent report by Reuters.