CAIRO -- Not everyone was pleased Tuesday when crowds in Tahrir Square revived chants of "Peaceful! Peaceful!" that were heard nine months ago during the uprising that ousted President Hosni Mubarak.

A group of young men, their eyes and noses red from tear gas fired at rock-throwing protesters nearby, shook their heads.

"Enough 'peaceful' already!" one said.

The latest demonstrations against the military leaders who replaced Mubarak are more explosive and violent than those in January and February, something that pro-democracy activists had warned might happen as the ruling generals stumbled in carrying out sweeping reforms.

Protesters hurl rocks and firebombs. Security forces fire tear gas, rubber bullets and bird shot. The number of wounded piles up at an average of 80 per hour. Angry cries of "thuggery" and "dirty government" echo among the buildings. The death toll has risen steadily.

The violence Monday and Tuesday centered around the headquarters of the Interior Ministry, which runs the police.

In the earlier demonstrations, protesters rarely approached the headquarters. But in a sign of the greater aggression in the past four days, they have marched repeatedly on the building, and were met by a heavy response.

Police and military around the ministry fired tear gas and moved in, beating and dragging away some of the activists.

The protests have reignited as feelings arose among many Egyptians that their revolution has been undermined by the military.

Trials of former regime members have stalled, the economy has deteriorated, streets are less secure, activists have been hauled before military tribunals, and the generals have been reluctant in giving an exact date for transferring power to a civilian government and parliament.

There are also complaints that little has been done to reform the security forces, which rights groups say still torture detainees. The lack of trials for those behind the deaths of about 850 people in last winter's uprising also has led protesters to target the Interior Ministry.

It is clear that some of the protesters and the black-clad police -- a hated symbol of the Mubarak era -- are acting as if they have scores to settle from January and February.

While a feeling of uncertainty loomed over the first uprising because many Egyptians at the time thought the ouster of Mubarak to be a nearly impossible task, the protesters this time around are determined not to leave until Field Marshal Hussein Tantawi resigns.