Egyptian police opened the streets of north Cairo on Wednesday to political protests against and in favor of President Hosni Mubarak, giving the opposition a chance to argue its case in public.

For the first time since anti-Mubarak street protests began in December, the Egyptian authorities did not deploy riot police to pen in an opposition demonstration.

The Movement for Change, which overlaps with the better-known coalition called Kifaya, or Enough, took advantage of the vacuum to march through the streets of Rod el-Farag, a working-class residential quarter north of the city center.

Several hundred protesters chanting "Down, down with Mubarak" and other slogans paraded about 400 yards down a main artery and then back to where they had started. A smaller group of Mubarak supporters marched down the other side of the street, chanting allegiance to the president.

The organizers said they were surprised at the absence of the usual lines of hundreds of riot police in black uniforms. They linked that absence to a visit to Cairo on Monday by U.S. Secretary of State Condoleezza Rice, who criticized the government for allowing violence against demonstrators. Traffic police officers at the scene said they had no explanation.

The anti-Mubarak group took up a new chant: "America, give him a visa. And take him with you, Condoleezza."

A few police officers kept the demonstrators to the sides of the streets so that traffic could pass, but unlike on previous occasions, the police did not stop people from joining in.

After the chanting stopped, knots of 10 to 20 people each gathered at a bus station to hear informal representatives of the two sides argue their case in public debate -- another unexpected development. Mubarak supporters challenged the opposition to propose a better leader. The opposition tried to explain its concept of free and fair elections.

Marchers organized by the Movement for Change rally in Egypt's capital.