ALEXANDRIA, Egypt - Violence erupted between Egypt's divided camps on Friday, the eve of the final round of a referendum on a constitution that has polarized the nation, as Islamists and their opponents pelted each other with stones while police fired tear gas in the streets of the Mediterranean city of Alexandria.

The draft constitution, which would bring a greater implementation of Islamic law to Egypt, is expected to be approved Saturday. The first round of voting took place Dec. 15 in 10 of Egypt's 27 provinces. Turnout was put at 32 percent. The remaining provinces vote Saturday.

The new clashes - in which opponents of Islamists set fire to cars and dozens of people were hurt - illustrated how the new charter is unlikely to ease the violent conflict over the country's future. For a month, Egypt has been torn between Islamists and their opponents, who accuse President Mohammed Morsi and his Muslim Brotherhood of trying to unilaterally impose their will on the country.

Meanwhile, Morsi was already gearing up for the next steps after the constitution's passage, making a last-minute appointment of 90 new members to the parliament's upper house, a third of its total membership. Current rules allow him to do so, but if he waited until the charter was passed he could only appoint 10.

The body is normally so toothless and ignored that few Egyptians bothered to vote in elections for it this year, allowing an almost total sweep by the Brotherhood and other Islamists. But once the charter is passed, it will hold lawmaking powers until elections for a new lower house - not expected for several months.

Friday's appointments added to the tiny ranks of non-Islamists in the upper house, known as the Shura Council, but preserved the Islamists' hold.

A spokesman for the main opposition umbrella National Salvation Front dismissed the appointments, accusing Morsi of setting up a token opposition much like ousted autocrat Hosni Mubarak did.