Voters in Egypt have overwhelmingly approved a new, military-backed constitution in two days of polling, according to unofficial results released Thursday by individual election committees across the country.

The national election commission has not announced official results from the voting that ended Wednesday. But state news media reported Thursday that 98 percent of voters in 25 of Egypt’s 27 provinces cast “yes” ballots in the referendum, which was billed as a mandate for the interim government that replaced ousted Islamist president Mohamed Morsi’s administration.

The vote was also seen as a possible catalyst for a presidential bid by Gen. Abdel Fatah al-Sissi, Egypt’s armed forces chief and defense minister.

But the overwhelming approval for the charter also called up memories of the one-sided election results that marked the three-decade rule of Hosni Mubarak. Ballot-rigging and voter intimidation were rampant during his presidency, which ended with his overthrow in 2011, and he often secured more than 90 percent of the vote in presidential polls widely deemed fraudulent.

The reported turnout of about 35 to 38 percent of eligible voters this week did not significantly surpass the percentage of Egyptians who voted in a 2012 referendum on a constitution drafted by Morsi’s Muslim Brotherhood and its Islamist allies, but that constitution passed with just 63 percent approval.

The Mediterranean province of Matrouh, where Islamists are popular, had the lowest turnout Tuesday and Wednesday, just 20 percent of eligible voters.

Election monitors reported serious violations and irregularities in the voting, including intimidation of the constitution’s opponents, but they have not formally accused authorities of fraud or ballot-stuffing.

“Politically motivated violence, intimidation and repression from state and non-state actors limited and conditioned citizens’ political and electoral participation,” the Berlin-based global corruption watchdog Transparency International said in a statement released Thursday.

In one instance, a local anti-corruption group called Shayfeencom (“We Are Watching You”) reported that one of its election observers was detained and tortured by security forces in the Suez Canal city of Port Said after an altercation at a polling station Wednesday.

Yet many Egyptians view passage of the constitution as a stepping­stone toward political and economic stability after years of turmoil.