NAIROBI, Kenya — A fire swept through a market and nearby homes in central Nairobi early Thursday, killing at least 15 people and injuring 70 more.

The blaze broke out in a timber yard around 2:30 a.m., officials said, and spread through the Gikomba market, nearby apartments and shanties before it was contained, about 90 minutes later.

Located in the dense city center, Gikomba is the heart of a huge informal market, selling everything from secondhand clothes to hardware. It has been damaged several times by fire, but the cause of the blaze on Thursday has not been established.