Egyptian supporters of President Mohamed Morsi shout slogans during a rally in the Mediterranean coastal city of Alexandria on December 21, 2012. Running clashes between rival protesters erupted in Egypt's second city Alexandria, on the eve of the final round of a referendum on a new constitution backed by the ruling Islamists.(Credit: AFP/Getty Images)
(AP) -- The head of Egypt's election commission says the new constitution has passed with a 63.8 percent "yes" vote in a referendum.
According to official results announced Tuesday, 32.9 percent of voters participated.
The announcement turns the Islamist-drafted charter into the country's first constitution after the uprising that forced Hosni Mubarak out of office after nearly 30 years of authoritarian rule.
The opposition had campaigned against the constitution, charging that it will usher in Islamic rule in Egypt and restrict freedoms. It has vowed to challenge the results.
Judge Samir Abou el-Maati, the head of the electoral commission, denied allegations that judicial supervision was lacking in the vote.
The official results closely mirror unofficial results announced by the Muslim Brotherhood, the main group that backed the charter.