DAKAR (Reuters) - Nine children were burnt to death in a fire that broke out while they were sleeping in a crowded room at a Koranic school in the Senegalese capital Dakar, witnesses said on Monday.

The fire occurred late on Sunday while some 40 children were asleep in a single room inside the ramshackle building with wooden walls and zinc roofing in the residential district of Medina, local residents said.

"When the fire started, a fire brigade truck came but could not get access to the site because of the narrow road leading to the house," restaurant worker Saliou Gano, 45, told Reuters.

Dakar Mayor Khalifa Sall told RFM radio the ramshackle development of the Senegalese capital made it impossible for emergency services to operate in its sandy alleys and backstreets.

Thousands of children from rural areas are sent to Dakar by poor parents to study at Koranic schools. With no money to pay for lodging, many of them end up begging on the streets.

(Reporting by Diadie Ba; Editing by Michael Roddy)