I was passing by Tahrir Square today before I go back to the US tomorrow. All streets to the US Embassy compund were blocked and barricaded by Security forces. Many young people 12 and over were charging at police and throwing stones. Police responded with tear gas. Protestors who are mostly very young people would pick up the tear gas canister and throw it back on the security forces or in the nile. I got closer to where young people were charging at the police on the Cornish St . Police started throwing tear gas; my eyes started burning fast and I started running back. I managed to get few video shots of the tear gas and young people charging at the police. It was turning into a game of throw and catch. Police will fire gas canisters and young people will catch it and throw it back at them or in the nile to the right. Gas masks were being sold in the Square but not every protester had one. There were ambulances nearby and I got treated from the tear gas. 

About the tear gas experience it was terrible, I felt I was suffocating and I  almost fainted.