The Lawrence of Arabia star, 79, was conducting interviews and posing for photographs on the red carpet at the event when the woman reportedly offended Sharif with a remark. He suddenly became angry, ranted at the woman in Arabic and then lashed out at her.
One eyewitness took to Twitter.com to blog about the alleged altercation, writing, "Omar Sharif just hit a woman. Very stupidly, in front of a camera."
But the reporter brushed off the incident and smiled as she posed for a photo with a calmer Sharif moments later.
Representatives for the veteran film star have yet to comment on the claims.
The altercation footage has since hit websites around the world.