A massive fire broke out in a 38-floor apartment and office building in South Korea's southern port city of Busan, news reports and fire officials have said.

Flames quickly spread through the building's main stairwell but were largely contained later in the afternoon, a local fire official in Busan said.

The fire official could not say how many people remained in the building, only that residents were still being rescued, some by helicopter from the building's roof.

YTN television showed footage of fire helicopters dousing the complex and a hose shooting water at it from a neighbouring building.

Busan, South Korea's second-largest city and a major seaport, is located about 250 miles southeast of Seoul.

The cable channel also reported that 37 residents were evacuated.

It said three were taken to a hospital and that one firefighter was injured. No deaths have been reported.