Cairo (CNN) -- Raging clashes between police and protesters in Egypt on Saturday left two people dead and 750 injured, the Health Ministry reported, prompting a call from a prominent grass-roots group for citizens to resist the military-led government.
The April 6 Movement, which figured prominently in the toppling of President Hosni Mubarak this year, issued a statement urging its members to descend on Cairo's Tahrir Square "immediately because resistance is the only solution."
"Down with military rule," the movement said.
The fighting erupted earlier in the day when police worked to clear the area of people who remained in the square after Friday's massive protests in Tahrir. Tens of thousands of Egyptians turned out Friday to protest plans for a constitution that would shield the military from public oversight.
As evening came Saturday, police blanketed the square and fired tear gas. The security forces soon withdrew and stationed themselves at the Interior Ministry. Warning shots were heard throughout the day.
Thousands of protesters remained at the scene. They chanted against the Supreme Council of the Armed Forces, which rules Egypt, and Field Marshal Mohamed Hussein Tantawi, the head of the council who is effectively the interim ruler of Egypt.
Protesters threw Molotov cocktails and rocks and torched a police van. Scuffles broke out on side streets and clouds of smoke rose from burned tires, witnesses said.
Clashes between protesters and police also reportedly broke out in the cities of Suez and Alexandria.
Two people died after being shot -- one in Cairo, one in Alexandria -- said Adel al-Dawi, a spokesman for the Health Ministry. State media reported that 750 people were injured, citing the Health Ministry. The Interior Ministry also said 20 police officers have been injured and eight people have been arrested.
"We sent hundreds of Central Security Police Forces and forced out the remaining several hundred protesters who refused to go home. We arrested four thieves and thugs who acted aggressively and beefed up security in and around square overnight," Interior spokesman Alaa Mahmoud said earlier Saturday.
The Cabinet held an emergency meeting to discuss the recent clashes and warned they could have a dangerous impact on Egypt, state media said.
The Friday throng, dominated by Islamist parties but including secular protesters as well, turned out ahead of upcoming parliamentary elections set to begin on November 28.
Mahmoud said the "Islamists and revolutionaries had left as they promised not to have a sit-in." But stragglers remained, and he said many of the people who stayed in the square were families of those injured during the upheaval earlier this year that led to Mubarak's departure and the ushering in of the supreme council as interim rulers.
Yousri Hamad, the official spokesman of the Al Noor Salafi Muslim political party, said he thinks that the violence could affect election plans.
"The protesters are a bunch of kids that attacked the security forces which is a red line and could delay elections," Hamad said.
The military said it wants to transfer power to a civilian parliament and president, but many citizens are dissatisfied with the pace of the transition and the resolve of the military rulers.
But protesters were upset Friday about proposed principles for the constitution, in which the military's budget would not be scrutinized by civilian powers. They worry that the military would be shaped as a state within a state.
The outpouring reflected the power of Islamist forces in Egypt, particularly the Muslim Brotherhood's Freedom and Justice Party. A leader of that group called for restraint in the wake of Saturday's clashes, state media reported.
The demonstrations occurred a day after hundreds of Coptic Christians marching in Cairo were attacked by unknown assailants. At least 32 people, including two police officers, were injured.
They were heading to Cairo's Tahrir Square to commemorate the deaths of pro-Coptic protesters killed in clashes in the Egyptian capital last month.
Problems between Egypt's Muslim majority and the Copts have been on the rise in recent months, with a number of violent clashes reported between the two groups.
Protests also stretched to the United States on Saturday, where demonstrators gathered in the nation's capital in opposition to military rule in Egypt.
Protester Amin Mahmoud, a member of a group called the "Egyptian Organization for Change USA," said Egypt's military "has been taking civilians before military courts, and we are against that.
"They are torturing a lot of young revolutionaries, accusing them of being traitors, and that is not true," he said.
CNN's Alexander Hunter contributed to this report