Port-au-Prince, Haiti ? Former Prime Minister Yvon Neptune, looking frail in the wake of his on-and-off hunger strike, was freed Thursday after two years in prison and ferried away by an ambulance escorted by heavy security.

Neptune won his freedom one day after he spoke to the media for the first time since his arrest and vowed to fight what he called the “machine of injustice” responsible for his prolonged imprisonment without trial.

“The machine of injustice must stop,” the barefoot Neptune told a small group of reporters in the barren bedroom that served as his cell. “This is not something that concerns just me. It is something that concerns all the Haitian people who don’t have the means to face the machine of injustice.”

Neptune’s release brought a small measure of respect and good will toward the two-month-old government of President Rene Preval, who has called for national reconciliation in the aftermath of a revolt that toppled former President Jean-Bertrand Aristide in 2004. Neptune served as prime minister for Aristide.

Human rights activists hailed the new government’s decision to free a man they had long considered as a political prisoner jailed by the U.S.-backed interim government that preceded Preval.

But scores of Aristide supporters and several thousand alleged criminals remain jailed without trials.

Neptune made no statements after his release and was taken to a hospital for a medical checkup. It was unclear what the next legal step in his case will be.

The 59-year-old Neptune was jailed in connection with a 2004 massacre of Aristide opponents near the western port city of St. Marc. He has demanded his unconditional release and last year refused a deal that would have allowed him to leave for the neighboring Dominican Republic. An appeal seeking that the charges be dropped remains at a standstill since October.