Taiwan authorities said on Thursday that more than 40 people are feared to have died after a fire broke out in a residential building in the southern Taiwanese city of Kaohsiung.

The fire erupted in the 40-year-old building in Kaohsiung’s Yancheng district in the early hours of the morning and was extinguished around dawn.

Kaohsiung fire chief Lee Ching-hsiu said firefighters were still going through the building and it looked like the number of dead could exceed 40 people.

Mayor Chen Chi-mai said the building was partly abandoned, having previously been host to restaurants, karaoke lounges and a cinema.

The government is investigating the cause including whether arson was to blame.