Thousands of activists on Saturday marched on the controversial training base for soldiers from Latin American militaries formerly known as the School of the Americas, at Fort Benning, Georgia, to demand its closure.

"The figure that we have now, very conservative, is more than 4,000 people in Fort Benning Road, the main entrance to the military base," Hendrik Voss, spokesman for the School of Americas Watch (SOAW), told AFP.

The institute, which each year trains hundreds of soldiers sent over from Latin America military, has renamed itself the "Western Hemisphere Institute for Security Cooperation," or WHINSEC.

The activists called on President Barack Obama to close the school, which they argue costs US taxpayers millions of dollars that, they point out, "could be used to improve or build more public schools in the United States."

Actor and supporter Martin Sheen, who was expected to address the crowd at Fort Benning on Sunday, said in a statement released by the activist group before traveling to Georgia that it was "from numerous acts of courage that human history has been shaped," in a call for solidarity with the effort.

Seeking to emulate the ongoing "occupy" movement in the United States, where groups have camped out in New York, Washington and in major cities across the country, SOAW said the weekend rally at Fort Benning aimed "to transform Fort Benning from a place that trains assassins into a place of memory and nonviolent resistance."