Hundreds of Egyptian protesters attempted to storm a building belonging to the internal security service in Alexandria in an outpouring of anger at the agency blamed for some of the worst human rights violations during ousted President Hosni Mubarak's rule.
Officers inside the building opened fire on the crowd on Friday, injuring three demonstrators, according to a medic and one of the protesters.
Tensions remain high even as Egypt's military, which took control of the country after Mubarak stepped down on Feb.
11, takes steps to meet the protesters' demands before a promised return to civilian rule. One of the protesters' key remaining demands is for the dismantling of Egypt's State Security Agency.
Earlier Friday, crowds in Cairo's Tahrir Square celebrated the military's choice of a new prime minister to replace the one Mubarak had appointed. The new premier, Essam Sharaf, was carried on the shoulders of demonstrators to a podium in the square from which he promised the estimated 10,000 people gathered there that he would do his best to meet their demands.
In Alexandria, where some of the uprising's worst violence occurred, around 1,000 protesters encircled the State Security Agency building after nightfall and demanded that the officers inside come out or they would storm the building. Several fire bombs were hurled and four police cars were set ablaze, though one protester insisted they were not to blame and only threw rocks.
Shots were fired at the crowd and three people were injured, said an ambulance medic who spoke on condition of anonymity because he was not authorized to release information to journalists.
"It was coming from inside the building," said protester Mahinour el-Masri. She said a friend was among the wounded and had been hit by gunfire in the stomach.
Protesters then stormed into the building and scuffled with riot police inside before military forces intervened and took control of the building. El-Masri said they found shredded documents and files inside.
The Interior Ministry denied officers fired on protesters and accused the crowds that entered the building of seizing weapons and holding guards hostage.
A smaller crowd also marched toward a State Security building in Cairo but was stopped by soldiers from getting close.
Egypt's internal security services and police forces, which were given a free hand by emergency laws under Mubarak to suppress dissent, are some of the most powerful symbols of his regime.
In particular, the case of a 28-year-old Alexandria businessman allegedly beaten to death by two policemen in June set off months of small-scale protests and became a rallying point for a campaign against brutality by the police and security services.
A Facebook page started in memory of the man, Khaled Said, was used to send out the first call for large-scale anti-government protests on Jan. 25.
Since Mubarak's ouster, Egypt's military rulers have been trying to meet quell the anger.
It announced Friday that a referendum on constitutional changes to allow for competitive parliamentary and presidential elections will be held on March 19.
A day earlier, the army picked Sharaf to become prime minister and form a new Cabinet. He replaces Ahmed Shafiq, the last premier to be named by Mubarak. Shafiq's resignation was among the major opposition demands.
A former transport minister, Sharaf endeared himself to the protesters when he joined the demonstrations that forced Mubarak to resign.
"I draw will and determination from here," Sharaf told the crowd in Cairo's Tahrir Square Friday. "I will do my utmost to realize your demands," he said, pledging to step down if he fails.
Sharaf, a U.S.-educated civil engineer, served in the Cabinet for 18 months between 2004 and 2005.
His government will serve in a caretaker capacity until elections are held.
Besides Shafiq's resignation, the revolt's leaders want Mubarak's National Democratic Party dissolved. Other demands include the prosecution of security officials behind the deaths of protesters and the release of political prisoners.
"I am here because I get my legitimacy from you," Sharaf, in a gray business suit but no tie, told the demonstrators. He called on the protesters to turn their attention to "rebuilding Egypt." "I pray to God that I see an Egypt where free opinions are voiced outside (prison) cells and security agencies are in the service of the nation."
Sharaf is faced with the daunting task of restoring a sense of normalcy in the country, where police forces have largely disappeared from the streets and there is a growing sense of insecurity. The stock market has been closed for over a month, and since Mubarak left there have been countless labor and other strikes. Eleven universities were set to reopen on Saturday.
The constitutional changes to be voted on would open presidential elections to competition and impose a two-term limit on future presidents _ a dramatic shift from a system that allowed Mubarak to rule for three decades.
The proposals address a number of the demands of the reform movement. But many say the changes don't go far enough and debate is still under way over which election should come first.
Since it took charge of managing Egypt's affairs, the military has promised to hand power to a new government and elected president within six months. It disbanded both houses of parliament and promised to repeal the emergency laws, though only when conditions permit.