DHAKA (Reuters) - A fire swept through a garment factory on the outskirts of Bangladesh's capital on Saturday, killing at least nine people and injuring more than 100, police and witnesses said.

The fire at the nine-story factory in the Ashulia industrial belt started on the ground floor and quickly spread. Firefighters took nearly five hours to extinguish the flames.

Most of the victims died as they jumped from the building to escape the flames, a police official said. The death toll could rise, witnesses said.

The cause of the blaze was not immediately clear.

Bangladesh has around 4,500 garment factories that make clothes for brands including Tesco, Wal-Mart, JC Penney, H&M, Marks & Spencer, Kohl's and Carrefour.

Readymade garments make up 80 percent of the country's $24 billion annual exports.

(Reporting by Ruma Paul; Editing by Jon Hemming)