Egyptian security forces fired tear gas and rubber bullets Saturday during hours-long clashes with protesters who were trying to set up a permanent protest camp in downtown Cairo’s Tahrir Square.

The fighting, which left at least one person dead and more than 600 wounded in Cairo, sparked calls for a new revolt against military leaders who activists accuse of reneging on their promise to promptly hand over power to elected officials.

Saturday’s confrontation with police was reminiscent of the most violent days of the 18-day revolt that drove President Hosni Mubarak out of power in February, as liberal and Islamist activists worked jointly to battle riot police officers.

Coming just nine days before Egypt is to hold parliamentary elections, the unrest added to the uncertainty over whether the country’s leaders will manage to oversee a smooth transition to civilian rule.

Thousands of demonstrators were attempting to stay put in Tahrir late Saturday night, vowing to remain there until the military gives up power.

“I am going to participate in the sit-in until SCAF hands over power to a civilian government,” said Manal Ali, a 26-year-old accountant, referring to the Supreme Council of the Armed Forces.

Prime Minister Essam Sharaf urged protesters to go home. The Ministry of Interior, which controls the police, said in a statement that its officers had shown restraint and that their deployment was intended to maintain security and order. The government appeared to refrain from deploying soldiers.

Activists decried the use of rubber bullets fired into protesters’ faces, which in at least a couple of cases resulted in serious eye injuries.

“This is another big leap toward the abyss,” said Hossam Bahgat, a prominent human rights activist.

Protesters set at least one police vehicle on fire and lobbed rocks at police officers in riot gear as the two sides struggled for dominance of the iconic square.

The crackdown began after noon, when police moved in to tear down a few tents demonstrators had set after a massive demonstration on Friday.

“They removed our tents and our blankets and beat us with sticks,” said 39-year-old Fathy el-Moughazy, one of the protesters who had stayed at the square overnight after the Friday protest.

The protest escalated after demonstrators seized and destroyed one of seven central security vehicles that had been attempting to flee Tahrir Square amid a shower of rocks.

“Now we have our revolution back,” said Mustafa Fa’ir, a member of the January 25 youth movement.

By nighttime, Islamist leaders called on their followers to head to the square to back up the ranks of demonstrators, which throughout the day had been predominantly young and liberal.

In addition to the protester killed in Cairo, the Associated Press, citing an unidentified security official, reported that at least one demonstrator was killed in the city of Alexandria.

Many protesters and bystanders in Cairo lamented the violence, and some criticized the activists.

“We’re taking the country down,” Mohamed Ali Mohamed, 51, said. “This is wrong of the protesters. It’s not a demonstration, it’s thuggery. The Interior Ministry did right today.”

Tens of thousands of demonstrators on Friday demanded that the interim military rulers surrender power to elected officials by next spring, rather than sticking to their proposed timeline of holding presidential elections no sooner than 2013.

Hassieb is a special correspondent.