CAIRO, Egypt — Anger at Egypt’s ruling military council exploded into hours of fierce clashes in downtown Cairo and other cities Saturday that left two protesters dead and 750 wounded in violence that threatens the landmark elections scheduled to begin in nine days.

The battle for the iconic Tahrir Square began mid-morning Saturday when security services forcibly cleared the area of activists who tried to camp there in protest of the military council, which critics say is trying to expand its powers and delay the transfer of power to a civilian authority. The protesters had lingered from the previous day, when tens of thousands of Egyptians flooded the square in a peaceful anti-military rally that was dominated by Islamist factions.

On Saturday, some Islamist leaders and youth movements sent reinforcements to defend the mostly liberal and leftist protesters after live TV footage showed security personnel firing on them with birdshot and tear-gas canisters.

Egyptian Prime Minister Essam Sharaf pleaded with protesters to leave the square, but by late Saturday night, the riots were metastasizing as thousands of revolutionaries in Alexandria, Suez and other big cities took to the streets in solidarity.

“The whole city is paralyzed, protests are blocking main streets. The army is standing aside and there is no police at all,” said Mahmoud el Anani, a shop owner in Suez who was interviewed by phone from the canal city. “It’s turning into chaos … if they cannot secure the city now, how will they secure elections?”

Analysts said the rapid escalation from an event that began with a few dozen protesters shows that the military is incapable of securing the country when polls open Nov. 28. Protesters said they no longer trust the ruling generals to carry out the goals of the uprising that toppled President Hosni Mubarak, and called for a “second revolution” to prevent the country from slipping back under authoritarian rule.

Even the Egyptian Cabinet appeared worried.

“What is happening in Tahrir is very dangerous and threatens the course of the nation and the revolution,” the Cabinet said in a statement.

Several influential Islamist politicians from both the Muslim Brotherhood and the more fundamentalist Salafis seized on Friday’s showdown to reiterate their campaign promises of upholding revolutionary values and reining in military powers. Islamist candidates, along with dozens of their followers, arrived in the square after nightfall.

Mohamed el Beltagi, a senior Muslim Brotherhood figure and one of its Freedom and Justice Party’s most popular candidates, said he and his supporters went to the square to protest a “crime against the Egyptian people.” He said authorities must respect protesters’ right to gather peacefully.

“We didn’t call for the sit-in or join it, but we are here to assure that all Egyptians have the right to protest, and to condemn the aggression led by the police force against peaceful protesters,” Beltagi said. “It’s a moral issue and has nothing to do with the elections or our campaign.”

A liberal revolutionary youth group, the April 6 Movement, also mobilized its supporters and joined the Tahrir Square fight. Soccer clubs, professionals, laborers and a few women joined the anti-military sit-in.

Ambulances raced through the narrow arteries of downtown Cairo toward the scene, as battles raged down side streets. Amateur video posted online by activists showed protesters attacking an armored police vehicle, tipping it over and setting it on fire. Other videos showed riot police beating protesters with batons, and both sides hurling rocks at one another.

Most of the wounded suffered head injuries from projectiles; many others complained of respiratory problems from tear gas. The health ministry announced that 442 of the wounded were treated at the scene, with 65 more serious cases transported to hospitals.

The toll continued to rise as the battles continued for hours. The first Tahrir death — reportedly Ahmed Mahmoud, 23, who was shot in the chest — was confirmed just before midnight local time. After 1 a.m., Al Jazeera reported the death of another protester, in the port city of Alexandria.

By early Sunday Egyptian time, the protesters had barricaded themselves in the square and police were returning to the area. Witnesses said warning shots were fired as clashes resumed around the interior ministry and other sensitive sites. Volunteers set up a makeshift clinic in the square, yet another reminder of the 18-day uprising against Mubarak.