TOKYO -- A fire broke out in a wooden two-story apartment building early Sunday in Nishinari Ward of Japan's Osaka, leaving two dead, local media reported.

A resident alerted the fire department just before 5 am local time, reporting that smoke was filling the first floor, according to national broadcaster NHK.

Firefighters managed to bring the blaze under control in about an hour, but two apartment buildings, covering a total area of approximately 400 square meters, were burned.

According to police and fire officials, three people were taken to the hospital. A man and a woman were pronounced dead, while another man sustained minor injuries.

The fire occurred in a densely populated residential area about 500 meters southeast of Dobutsuen-mae Station on the Osaka Metro. Authorities are working to confirm the identities of the deceased and investigate the cause of the fire.