They also formed a human chain, in more of a symbol than a show of force because of the sheer number of pro-Mubarak demonstrators.
Television showed the two sides separated by trucks, but pelting each other with bottles and stones.
Opposition protesters charged that those supporting the president were Mubarak's thugs, paid by the administration to disrupt their largely peaceful gathering. But the Ministry of Interior denied that was the case and that security forces were among protesters in Tahrir Square.
Police were absent once again today, though officers in civilian clothes were seen roaming the crowds. The army, deployed to secure peace, stood mainly on the sidelines.
Internet was restored today and the government eased curfew hours, but that has had little impact on the demonstrations in the heart of Cairo. The number of protesters in Tahrir Square was considerably less than Tuesday, which marked the largest day of gathering in the protests that started last week.
Mubarak announced late Tuesday that he would finish his term, but not seek re-election in the September elections, but that did little to appease protesters, who are demanding his immediate removal.
Muhammed ElBaradei, the Nobel laureate who has emerged as a de facto opposition leader, dismissed Mubarak's move as a "trick" to stay in power.
"What is happening now is the continuance of a regime that knows that their people don't want them in power," ElBaradei told Al Jazeera. "What is happening now is security forces are attacking the Egyptian protesters. This was proven when we found that they had changed their clothes on side roads before coming in."
Mubarak's announcement has left many people conflicted about the state of the country. Some, who want to see him removed immediately, say his promises of stepping down and a speedy election are not enough.
"This is a very bad feeling. We feel deceived," one teary-eyed woman told ABC News.
Others say they are nervous about Egypt's future in Mubarak's absence.
"They are looking for the stability of the country. Maybe if he left, and one day the country will fall," another woman told ABC News.
Mubarak's announcement Tuesday that he will stay through his term did little to quell protesters calling for his immediate removal.
"My first responsibility is to restore the security and stability of the homeland, to achieve a peaceful transition of power in a way that will protect Egypt and Egyptians, and that will allow for responsibility to be given to whomever the people elect in the forthcoming elections," Mubarak said in his second speech to the nation since the protests began a week ago.
A stoic Mubarak announced that he will ask the new government to speed up elections, which are scheduled to be held in September. He vowed to honor people's demands, to protect the citizens honestly and end corruption.
Striking a patriotic tone and emphasizing his military background, the 82-year-old president, who has held on to power for 30 years, defended his own record and suggested he will die on Egyptian soil even when he steps down.
"I never wanted power or prestige, and people know the difficult circumstances in which I shouldered responsibility. ... I have spent enough time preserving Egypt," Mubarak said. "History will judge me."