Thousands of Egyptians filled Cairo's Tahrir Square on Wednesday, exactly one year after the start of the revolution that ousted longtime Egyptian ruler Hosni Mubarak but, many say, accomplished little else.

At times the mood in the square was somber and tense amid fears that violence could break out between protesters and the military.

Many holding banners chanted against the country's military leaders. But some celebrated the anniversary and said Egypt has progressed since Mubarak's ouster.

"This time last year, every person in Egypt was enslaved to Mubarak's regime, and those who dared speak or write about his tyranny paid a high price," said Yasmeen Khalil, a teacher. "Yes, the revolution may not be complete, but I think we have come a long way, and no one can deny it.

But some pro-democracy activists, frustrated by what they say is the slow pace of change, have clashed with the military in Cairo's streets in recent months.