Thousands of protesters have occupied New York City's Times Square, buoyed by a day of demonstrations around the world in support of their monthlong campaign against corporate greed.

Police in riot gear and mounted on horses tried to push people out of the square in an attempt to funnel the crowds away.

It was just one of several protests held throughout the United States and across the world Saturday inspired by the “Occupy Wall Street” movement.

In Rome, police fired tear gas and water cannons when a small number of the hundreds of protesters filling the streets broke away from the main group and ran amok, smashing windows and lighting fires. Police presence is heavy in the Italian capital.

In London, scuffles broke out between police and protesters among the hundreds gathered near St. Paul's Cathedral.

Demonstrations also took place in Australia, New Zealand, Spain, Germany, and France, where members of the Group of 20 financial powers are meeting in Paris to discuss the European economic crisis.

Many demonstrators are protesting inequality between the rich and poor, calling themselves “the 99 percent” in contrast to the “one percent” of people who they say account for most of the world's wealth.

Other causes the protesters espouse include abolishing capitalism, lowering college tuition, and ending the wars in Iraq and Afghanistan.

In Japan Saturday, small demonstrations centered on ending the use of nuclear power.

The Occupy Wall Street protest began on September 17 with a small group of activists accusing what they called “corporate America” of fostering a growing economic divide between the wealthy, and the poor and middle class. The movement has gathered momentum despite criticism that it lacks a central focus.