Some 50 houses in the densely populated Suan Plu neighborhood caught fire by mid-afternoon, said Sathorn district administrator Prasarn Bamrungphan. There are about 200 wooden houses and corrugated steel shacks in the area.
Firefighters had difficulty reaching the area and feared strong winds could spread the blaze to nearby buildings, including a police and immigration center and luxury apartment complexes. There are embassies and five-star hotels in the area, but not in the immediate vicinity.
Police ordered the evacuation of two five-story apartment buildings where officers live, one of which had caught fire, firefighter Col. Wichai Krawatanasiri said.
``The fire is getting worse and has engulfed a police apartment building,'' he said.
Hundreds of people, some of them weeping, watched from sidewalks as huge plumes of black smoke rose above the neighborhood. Some residents ran from their homes clutching personal belongings such as television sets, computers and pets.
``We didn't have time to get anything out,'' said Cang-on Porang, a 48-year-old housewife. ``The smoke just started rising.''
Chaingam Kiewsaad, 33, said she fled her house when the fire spread nearby. ``It's probably all gone,'' she said, sobbing. ``I couldn't get anything out. Even my car is in there.''
The cause of the fire was not immediately known.