Amir served a 16-and-a-half-year sentence for conspiring in the 1995 murder of Rabin with his brother, Yigal, and his friend Dror Adani, Haaretz reported.
Protesters -- both for and against Hagai Amir's release -- gathered outside Ayalon Prison Friday morning for Amir's release.
Dror Morag, secretary-general of the left-wing Meretz Party, responded to Amir's release by saying, "We are here to prevent the next Yigal Amir. We must remember that even today, this man does not regret his actions, nor apologize for them."
Eyal Moutner, of the Working and Learning Youth movement, said Friday was a "sad day for Israeli democracy."
"This day, after 16 and a half years, a man who conspired to assassinate Rabin is released. During this whole period, he did not express any regret over the actions of his brother. We stand against those who embrace Hagai Amir," he said.
Right-wing activist Noam Federman clashed with left-wing protesters.
"The man deserves to be freed, he deserves to be congratulated. Hagai Amir did not do anything. The state of Israel could not believe that Yigal Amir acted alone, and sought to find for an underground organization. Hagai did not do anything, he did not even know that there was a plot to kill the prime minister," said Federman.
"Rabin caused the deaths of thousands of Jews," Federman continued, "I do not support murder, but even today, I'm not shedding any tears for Rabin]. We will greet [Amir] warmly and throw him a party."
Amir, who was convicted of conspiracy to commit a crime and unlawful possession of a firearm and making threats on the life of former Prime Minister Ariel Sharon -- which he was charged with while in prison and served an additional year for, spent all of his time in prison in solitary confinement, Ynetnews reported.
"All the attention was because it was Yitzhak Rabin who was killed. If [the victim] had been a regular guy, he would have gotten completely different treatment," a fellow prisoner said.
Yigal Amir is currently serving a life sentence for shooting Rabin on Nov. 4, 1995, at the conclusion of a peace rally in Tel Aviv.