The Nanfang Daily said 84 firefighters battled the blaze.
The Southern Metropolis Daily said in an online report that the victims were all women aged 18-20.
It said the cause of the fire was arson, according to an initial police and fire investigation.
A photo accompanying its report showed a four-story building, lined with windows on each floor, its front completely blackened. The fire had not spread to an adjacent building.
Senior provincial officials set up a team to investigate the cause of the fire and step up safety measures to avoid similar fatal fires, Guangdong's emergency department said. The factory made underwear, it said.
Last month, a fire at a clothing factory in Bangladesh killed 112 people and highlighted dangerous workplace conditions. Workers who survived the fire said exit doors were locked.
Written by Associated Press