CAIRO –– Egypt's opposition said on Sunday that it will appeal the results of a referendum that ruling Islamists said approved a new constitution, claiming that voting was riddled with "fraud and violations".

The announcement was made by the opposition National Salvation Front the day after the second and final round of the referendum that President Mohamed Morsi's Muslim Brotherhood said passed with 64 per cent support, according to unofficial early tallies.

"The referendum is not the end of the road. It is only one battle," said the statement, read by Front member Abdel Ghaffer Shokr at a Cairo news conference. "We will continue the fight for the Egyptian people."

Another Front member, Amr Hamzawy, said: "We are asking the (electoral) commission to investigate the irregularities before announcing official results."

The results had been due to be announced on Monday.