Clashes between rival demonstrators erupted on Friday in Egypt's second city Alexandria, on the eve of the final round of a referendum on a divisive new constitution pushed by Islamists.
Riot police, with orders to act "decisively," formed a barrier between several thousand Islamists and hundreds more opposition protesters and used tear gas to quell the street battles.
The interior ministry said in a statement that 62 people, among them 12 police conscripts, were injured in the clashes in which protesters torched two police buses. Police also arrested 12 protesters.
In the first round held in half of Egypt last weekend, Alexandria voted in favour of the constitution. It has seen clashes break out several times amid nationwide rallies both for and against Islamist President Mohamed Morsi.
Early this month in Cairo, the confrontations turned deadly outside the presidential palace with eight people killed and hundreds hurt.
The army has since deployed 120,000 soldiers to bolster 130,000 police tasked with maintaining security during the volatile voting.
The secular-leaning opposition sees the proposed constitution as weakening human rights and opening the way to creeping strict sharia-style Islamic legislation under Morsi. It is urging a "no" vote in Saturday's second round.
Analysts said it was almost certain the new constitution would be adopted -- but that such an outcome would not end Egypt's political crisis.
The instability is hurting the economy, which has been limping along since the popular uprising that ousted the 30-year autocratic regime of Hosni Mubarak early last year.
The International Monetary Fund has put on hold a $4.8-billion loan Egypt needs to stave off a currency collapse, and Germany has indefinitely postponed a plan to forgive $316 million of Egypt's debt.
The head of the National Salvation Front opposition coalition, former UN atomic energy agency chief Mohamed ElBaradei, warned in an online video that "the country is on the verge of bankruptcy."
He said "a solution is still possible," as long as Morsi was prepared for "sincere dialogue" and allowed a whole new constitution to be drafted through a more inclusive process.
Supporters of both sides have taken to the streets in an attempt to sway voters to their side of the debate in the run-up to the referendum's second round.
In Giza, a southwestern Cairo district that will vote on Saturday, an opposition campaign volunteer who give his name as Maher said he pointed out to people in the street those who remain "committed to the revolution and who betrayed it" -- implying that Morsi's Muslim Brotherhood had Egypt let down.
A pro-constitution campaigner there, Abdallah Hassan, said his counter pitch was to inform people of "the benefits that will come out of this constitution by voting 'yes'," principally stability after so many months of turmoil.
Analysts said that even if the draft charter were adopted, it would do nothing to resolve the festering political confrontation.
"Everything suggests the vote will go the way the Muslim Brotherhood wants," Hassan Nafaa, an analyst and commentator, wrote in the newspaper Al-Masri al-Youm.
"But the misleading conclusion it will take away is that there is an overwhelming victory allowing it to continue on its chosen path."