A total of 12 people were killed in a residential building fire on Tuesday night in Shantou City, south China's Guangdong Province, local authorities said Wednesday.

The blaze erupted at around 9:20 p.m. in the city's Chaonan District and was extinguished by around 10 p.m., according to the district's fire department.

Twenty people were trapped in the blaze, according to local authorities. Eight were rescued, eight were pronounced dead at the scene, and four died in hospital despite emergency treatment.

Preliminary investigations show that the building was a four-story, self-built concrete structure, with the fire affecting about 150 square meters.

Authorities in Shantou have launched an investigation into the cause of the fire, as well as citywide safety inspections. The city has rolled out measures to strengthen follow-up work, scene analysis and the inspection of potential safety hazards across Shantou.