RNA - Local paper, Okaz said on its website, citing the Civil Defence department that the laborers were working on the construction site when the roof fell through in Mecca, trapping the group under rubble, New Arab reported.
The cause of the collapse was not specified, however authorities confirmed the accident was under investigation.
Fifteen of the 18 Egyptians working on the building's metalwork needed hospital treatment.
On Wednesday, two Pakistanis died in a separate construction accident also in Mecca, where authorities are involved in several construction projects.
Last year, at least 10 construction workers from Pakistan and an Indian national died when a convention center collapsed in Qassim, Northwest of the capital Riyadh.
The plight of migrant workers in Saudi Arabia made headlines earlier this month when thousands of laborers from the Philippines were left stranded in dire conditions.
The Philippines responded to the situation, promising it will send government missions to Saudi Arabia to help thousands of jobless Filipinos left stranded across the kingdom after the plunge in oil prices.
The Philippine government estimates about 9,000 Filipino workers were affected, though the Manila-based labor rights group Migrante said as many as 20,000 could be in distress.
Asian activists and officials have said thousands of Indians and Pakistanis are also stranded in Saudi Arabia following the layoffs.
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