Three firefighters responding to the initial blaze are among the five killed, officials say, while more than 100 people were injured.
Another 10 people remain missing, including four factory workers and another firefighter, with rescuers on site searching for more survivors. The government has set up an emergency operation centre at the site to coordinate the rescue efforts and assist victims and their families.
The fire began at a factory located in Pingtung County in southern Taiwan on Friday night and continued until the morning, authorities said, when it was finally doused.
Photos from the site posted by Chinese state media show the factory covered in black soot with some fire brigade vehicles appearing damaged and partially covered by the debris.
Other videos showed a large fire burning in the factory on Friday night as plumes of black smoke rise into the sky.
Taiwan’s president Tsai Ing-wen in a speech in Taipei on Saturday offered her condolences to the families of the victims and said she would travel to Pingtung to visit those affected by the disaster, according to Taiwanese news outlet Focus Taiwan.
Chou Chun-mi, magistrate of Pingtung County, said in a Facebook post that the cause of the fire was still under investigation.
“Facing the grief of the family members, I could not say anything except to bow deeply, apologise, and express my deepest condolences,” she said in the post, after visiting the funeral home and meeting with victims’ families.
Authorities have said that gas being stored at the factory could be a potential reason for the fire and subsequent explosions.
Additional reporting by agencies