CAIRO: An overwhelming majority of Egyptians who voted on the country's new constitution backed the draft charter, a senior Egyptian official said Thursday, despite criticism from an international monitoring group of a clampdown on free speech ahead of the election.

The election official told The Associated Press that unofficial results after most of the ballots had been counted indicated that more than 90 percent voted "yes" on the constitution. He declined to give an estimate on the final turnout and spoke on condition of anonymity because he is not authorized to talk to journalists.

The interim government is looking not only for a strong "yes" majority but also a large turnout to win undisputed legitimacy and perhaps a popular mandate for the military chief, Gen. Abdel-Fattah el-Sissi, to run for president later this year.

An incomplete estimate published by the state news agency MENA showed a turnout of about 40 percent in Cairo and in Egypt's second largest city, Alexandria, both higher than in the 2012 referendum on the Islamist-backed constitution.

In the western border province of Masra Matrouh, which has a sizeable constituency of Islamists, turnout was the lowest, with only 20 percent of voters showing up, in comparison to 36.5 percent participation in 2012.

In the southern province of Assiut, considered a stronghold of Islamists but with a large Christian population, participation was slightly less than in 2012, dropping from 28 percent to 25 percent.

The Election Commission said results will be announced Saturday evening.

The vote held Tuesday and Wednesday was a milestone for Egypt's interim government, installed by the military after a July coup toppled Islamist President Mohammed Morsi following mass protests demanding that he step down.

Many considered the vote as key to restoring stability and supporting the current government in the face of continued opposition and protests from Morsi supporters.

But on Thursday, students rallied outside the campus of the University of Cairo and fought with security forces. Police fired tear gas, pushing the students back and later arrested 23, authorities said.

An Interior Ministry statement said it later deployed forces to clear clashes on campus between pro- and anti-Morsi students, and that one student was shot and killed. It was not immediately clear who shot the student.

The draft constitution is a heavily amended version of a charter written by Morsi's Islamist allies and ratified in December 2012 with some 64 percent of the vote but with a nationwide turnout of just over 30 percent. Morsi's Muslim Brotherhood group and other Islamist groups boycotted this week's referendum, calling it "illegitimate" and vowing to keep up protests.

The country's second-largest Islamist group, the ultraconservative Salafis, largely stayed away from the polls. That left traditional Islamist strongholds across Egypt seeing only a trickle of voters during the two-day balloting.

By contrast, long lines formed outside polling stations in Egypt's major urban areas and big cities, with crowds brandishing posters of the country's military chief, as men chanted in support of the army and women ululated.

Such patriotic outbursts followed an intense campaign by the government and the overwhelmingly pro-military media, which portrayed the balloting as key to the nation's security and stability.

In the weeks before the vote, hundreds of thousands of fliers, posters, banners and billboards urged Egyptians to vote "yes." Security forces arrested people calling for a "no" vote.

Kol Preap, the head of a Transparency International mission that monitored the referendum, said in a report Thursday that while authorities had responded to "a deep desire by the majority of Egyptians to move toward a democratic path," the political environment around the vote created "severe obstacles to advancing democracy."

Government actions such as arresting critics "undermined a level playing field for the promotion of diverse views," he said, citing "severe limits on the freedom of expression, association, and assembly" in the campaign ahead of the vote. His group had eight observers in 15 out Egypt's 27 provinces.

"The political context in the run-up to the referendum impaired conditions to hold a free and fair referendum compared with international standards," he said.

Local Egyptian groups that monitored the balloting said Thursday they had spotted some irregularities, such as instances of troops barring monitors from having access to the polling centers and the presence of pro-charter activists campaigning too close to the centers.

Following the referendum, Egypt's Interim President Adly Mansour is expected to announce a change in the army's transition plan and schedule presidential elections before the vote for the next parliament. This could give Egypt a new president before the summer.

SOURCE: AP