Two men convicted of the 1992 assassination of four Iranian opposition figures in a Berlin restaurant have been released early from prison, officials said Monday.

The release of Kazem Darabi, an Iranian, and Abbas Rhayel, a Lebanese, went ahead despite protest that the move could send the wrong signal about Germany's intention to fight terrorism.

Rhayel was freed from prison and deported from the country on Friday, according to Frank Wallenta, a spokesman for federal prosecutors in Karlsruhe.

Wallenta was unable to comment on Darabi, but security officials in Berlin who, declined to be identified because they were not authorized to speak about the matter, said Darabi had been released and was on his way to Frankfurt International Airport, where he was to be put on a plane to Tehran later in the day.

Wolfgang Wieland, a private lawyer who took part in the prosecution of the case and is a security expert for the opposition Greens party also confirmed Darabi's release. He decried it as undermining Germany's attempt to send a strong signal to terrorists.

"The early release of Darabi and the men behind him will be viewed in Iran as a weakness of the West and not as a generous move on the part of the German penal system," Wieland said.

The two prisoners were convicted of the Sept. 17, 1992, killing of Iranian Kurdish dissident leader Sadiq Sarafkindi and three of his associates in Berlin, and were sentenced to life in prison in 1997.

They were freed under a law that allows early release for foreigners who have served at least 15 years of their sentence, including the time served in pretrial detention.

Hamid Nowzari, a member of the Berlin-based Association of Iranian Refugees, which joined the prosecution during the trial as allowed under German law, also condemned the release.

"We think that Darabi's release is incompatible with Germany's fight against terrorism," Nowzari said.

In October, the family of missing Israeli air force navigator Ron Arad traveled to Germany to urge Federal Prosecutor Monika Harms to make the release contingent upon Tehran's releasing information about Arad.

Arad abandoned his Phantom jet over Lebanon in 1986 and his fate remains unknown. His family believes he is still alive in Iran.

The Mykonos trial -- so called for the Berlin restaurant where the killings took place -- raised an uproar when a German court ruled that Iran's spiritual leader Ayatollah Ali Khamenei and then-President Hashemi Rafsanjani had ordered the murders.

Both countries withdrew their ambassadors at the time.