Egyptian activists and security forces clash in Cairo

Violence between pro-democracy activists and Egyptian security forces escalated in central Cairo Friday as they threw Molotov cocktails, rocks and glass at each other.

Bricks and cement blocks rained down on protesters as men appearing to wear military uniforms tossed them off the top of a six-story building. Nearby, a Ministry of Transportation building burned as tents in an activist encampment in front of the parliament building also caught fire.

The military fired warning shots in the air and sprayed water cannons to disperse the crowd.

A Ministry of Interior official denied any police involvement.

"This situation has nothing to do with the police or the Ministry of Interior and we do not have forces at the site of the clashes," said Gen. Marwan Mustapha, a ministry spokesman.

A doctor at a makeshift clinic said he has treated dozens of protesters for cuts and injuries caused by glass and rocks.

"It all started when the military arrested one man, and then an hour later he emerged from building barely able to walk from the beating," said activist and video blogger Walid Nada. "His face and body and clothes (were) blotched with blood as the protesters carried him to makeshift hospital."

Activist Mona Seif identified the beaten man as Aboudi Ibrahim.

He "has no broken bones, but major bruises to the face, cuts, and harsh burns from electric shockers. We are filling a police report soon," she said.

CNN could not get an immediate response from the government about these claims.

Activists have camped outside parliament for weeks, protesting a military appointed prime minister.