LAGOS Aug 13 (Reuters) - The death toll from the collapse of a multi-storey building in Nigeria's capital Abuja three days ago has climbed to 23 from an initial two, the Nigerian Red Cross said on Friday.

The building, condemned as dangerous by the authorities and which was thought to be four or five floors high, tumbled down at around dawn on Wednesday in the Garki Area 11 neighbourhood of Abuja, south of the central business district.

"The rescue operation is now over. We are talking of 23 people dead and 10 injured," a Red Cross official told Reuters by telephone from Abuja, asking not to be named.

Substandard materials and disregard for building regulations mean such collapses are common in Africa's most populous nation, where infrastructure is old and poorly maintained.

Nigeria's Federal Capital Territory Minister Bala Muhammed, responsible for development in Abuja, said on Wednesday the building had been condemned by the authorities and developers had continued to add an additional floor despite the warnings.

At least 16 people were killed in two separate building collapses in Nigeria's commercial capital Lagos last year. (For full Reuters Africa coverage and to have your say on the top issues, visit: af.reuters.com/ ) (Reporting by Tume Ahemba; Editing by Nick Tattersall)

Those who engage in illegal construction of houses in Nigeria should be prepared to face the full weight of the law for their crime. We need a total restructuring of the rules and regulations guiding the construction industry in Nigeria.