The bus carrying over 50 workers of a company turned turtle apparently due to high speed and fell off a bridge into el-Mariotiya canal in Haram district in Giza.
Rescue forces rushed to spot after the accident and pulled out 12 bodies and the mangled bus out of the canal, said the spokesperson of the Ministry of Health, Hossam Abdel Ghafar.
The injured have been admitted to hospital and search operations are on to find other victims into the water.
Deadly road accidents claim thousands of lives in Egypt every year.