Ihab el-Manharawi, a 27-year-old protester injured in the January protests, said this week's violence reminded him of the deadly clashes with security forces earlier this year.
"When I saw that, I didn't care. ... I joined the protesters," he said. "The same old tactics ... People have changed, but they haven't. We wanted to believe it for a while, but the mindset (of Egypt's current leaders) is still the same. These people must leave."
More than 1,000 people were injured, MENA quoted Assistant Health Minister Abdul-Hameed Abazah as saying. About 900 were treated at the scene and more than 120 went to hospitals. Most of the injured suffered from gas inhalation, cuts, bruises and concussions, he said. At least 18 cars and 11 stores were damaged.
Ambulances, cars and motorbikes ferried the wounded to hospitals, while volunteer doctors and nurses treated others on the sidewalks.
Some protesters used scarves to shield their faces from tear gas. They pelted police cars with rocks and advanced when the riot police lines retreated. The main chant back in January and February — "the people want to oust the regime!" — was replaced by screams of "the people want to oust the field-marshal," a reference to Mohammed Hussein Tantawi, Mubarak's longtime defense minister and chairman of the Supreme Council of the Armed Forces that has taken over.
Some of the youth groups behind the uprising see Tantawi as tainted because he was a key member of the Mubarak regime. Critics also charge that Tantawi's policies are designed to keep the old order, and accuse him of deliberately stalling the process of purging Mubarak loyalists and failing to reform the Interior Ministry and its security agencies.
Mubarak's security chief, former Interior Minister Habib el-Adly, is on trial along with several of his top aides for ordering the use of deadly force against protesters. This week, his trial was adjourned until July 25, a decision that touched off clashes between relatives and police outside the courthouse. Some of the victims' relatives want Mubarak to be included in the case against el-Adly.
Mubarak has been under arrest at a hospital in the Red Sea resort city of Sharm el-Sheikh and has been charged with ordering the killing of protesters. Both men face the death penalty if convicted. Mubarak and his two sons go on trial Aug. 3.
The clashes began Tuesday evening after security forces refused to allow about 100 people to attend a ceremony at a Nile-side theater to honor the memory of people killed in the uprising. Many in the crowd said they were relatives of victims and fought with police to gain entry, pelting the theater with rocks.
The crowd then headed across the river to the state television building, where they persuaded relatives of victims staging a sit-in there to join the protest. Together, they marched to the Interior Ministry, where they clashed with police and later headed to nearby Tahrir Square.
They battled the police again until authorities ordered the police to pull back.
There were an estimated 6,000 protesters at the peak of the riots late Tuesday.
Wednesday's clashes centered on streets leading to the Interior Ministry close to the downtown campus of the American University in Cairo.
Tahrir Square was closed to traffic for most of the day and about 1,500 protesters remained out on the streets.