Cairo (CNN) -- Four people were killed and dozens more were injured when pro-democracy activists clashed Friday with Egyptian security forces in central Cairo, a government official said.
Two of the dead were teenagers and one was an Islamic scholar, said Dr. Hisham Shiha, a spokesman for the Ministry of Health. All four victims suffered gunshot wounds, with the fourth person shot in the back of the head, he said.
Adel Saeed, a spokesman for the general prosecutor, said an investigation is under way. "We are questioning 14 men detained at scene of clashes and we have a team now at two hospitals questioning the injured to understand how the injuries were inflicted," he said.
A separate team was at the morgues following up on the deaths, he said.
Meanwhile, people were throwing Molotov cocktails, rocks and glass.
Men wearing what appeared to be military uniforms tossed bricks and cement on protesters from atop a six-story building. A Ministry of Transportation building burned nearby, and tents in an activist encampment in front of parliament caught fire.
The military fired warning shots into the air and sprayed water cannon to disperse the crowd.
Shiha said nearly 100 people were hurt, including nine who were shot by live ammunition. Saeed said 12 people were charged with destroying public property.
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A Ministry of Interior official denied police were involved.
"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 clinic said he treated dozens of protesters for cuts and injuries caused by flying 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.
Activists have been camping outside parliament in protest of the military-appointed prime minister.