National Civil Protection authority spokesman Carlos Guerra says the injured have been taken to hospitals in the cities of Coimbra and Castelo Branco.
Television images showed a large rescue operation mounted on the approach roads Sunday, including more than 260 firefighters and at least one rescue helicopter.
The bus was reportedly traveling from the Spanish city of Badajoz to the tourist destination of Santa Maria da Feira. Civil Protection spokesman Rui Esteves says all the dead were Portuguese citizens.
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