Police have said as many as nine people may still be buried under the rubble in Lagos, the West African nation's commercial capital. But some newspapers estimated dozens of people could be trapped.
The unfinished two-story building collapsed Wednesday just after an unknown number of people sought shelter in it from the rain.
At least three bodies had been recovered by Wednesday evening and five survivors had been rescued. No officials could be reached for comment Thursday.
Firefighters and onlookers at first clawed through the rubble Wednesday with shovels and their bare hands in hopes of finding more survivors, whose cries could be heard above the din of the rescue.
Police were searching for the owner of the building, newspapers said, amid reports the collapse was caused by poor building materials.
According to one newspaper, two other Lagos buildings also collapsed during the downpour. There were no reports of deaths or serious injuries.
With its lack of inspectors, Lagos is plagued by building collapses, especially during in the rainy season.
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