A defiant Mordechai Vanunu (search) walked out of prison on Wednesday after serving 18 years for spilling Israel's nuclear secrets, saying he was proud of his actions and complaining he was treated cruelly by his jailers.

Vanunu, dressed in a checkered shirt and black tie, flashed victory signs and waved to hundreds of cheering supporters as he walked into the sun-splashed courtyard of Shikma Prison (search) in the coastal town of Ashkelon. Dozens of counter-demonstrators booed and shouted epithets.

In the courtyard, Vanunu, 50, held an impromptu news conference, his brother Meir by his side. Vanunu said he was given "very cruel and barbaric treatment" by Israel's security services.

"To all those who are calling me traitor, I am saying I am proud, I am proud and happy to do what I did," Vanunu said in accented and at times broken English. He refused to answer questions in Hebrew because of restrictions Israel has imposed, including a ban on speaking to foreigners.

Vanunu, who converted to Christianity in the 1980s, said he was mistreated because of his religion. He also said there is no need for a Jewish state and demanded that Israel open its nuclear reactor in Dimona (search) to international inspection.

"I said, Israel don't need nuclear arms, especially now that all the Middle East is free from nuclear weapons," he said.

He left the prison in a gray Mazda van as police dispersed a large crowd. His first stop was St. George, an Anglican church in Jerusalem's Old City. More than a dozen cars and motorcycles followed Vanunu's vehicle to Jerusalem, and a helicopter flew low overhead.

Israeli authorities have imposed a series of travel restrictions and other constraints on Vanunu, saying he still possesses state secrets. But Vanunu said he has no more secrets to reveal.

"I am now ready to start my life," he said.

Upon his arrival in Jerusalem, he was mobbed by reporters as the Anglican bishop of Jerusalem, Riah Abu El-Assal, escorted him into the church. Other clergy members embraced Vanunu, and a tearful Peter Hounam, the journalist who wrote the 1986 article that led to Vanunu's imprisonment, hugged him.

In 1986, Vanunu leaked details and pictures of Israel's alleged nuclear weapons program to The Sunday Times of London. Based on his account, experts said at the time that Israel had the world's sixth-largest stockpile of nuclear weapons.

The revelations undercut Israel's long-standing policy of neither confirming nor denying its nuclear capability. He was abducted by Israeli secret agents before the article was printed and subsequently convicted of treason in a closed trial.

Vanunu said Israel's Mossad spy agency and the Shin Bet (search) security services tried to rob him of his sanity by keeping him in solitary confinement for nearly 12 years. "I said to the Shabak [Shin Bet], the Mossad, you didn't succeed to break me, you didn't succeed to make me crazy."

Asked if he was a hero, he said "all those who are standing behind me, supporting me ... all are heroes."

"I am a symbol of the will of freedom," he said. "You cannot break the human spirit."

Hundreds of supporters and opponents squared off in shouting matches outside the prison ahead of his release. Supporters chanted "Mordechai is free," while counter-demonstrators held signs calling him a traitor and shouted curses.

"He won't get out of here alive," opponents screamed as Vanunu's adopted parents, Minnesota couple Nick and Mary Eoloff, arrived at the prison. Vanunu said he hopes to settle in the United States and study history.

While the crowds were vocal, there was no violence.

Anti-nuclear weapons activists from around the world had gathered at Shikma in recent days. Among his supporters, was British actress Susannah York and Nobel Peace Prize laureate Mairead Corrigan Maguire of Northern Ireland.

But Vanunu is widely detested in Israel.

"He's hell-bent to do as much harm as he can," Justice Minister Tommy Lapid told The Associated Press. "We will keep an eye on him, we will watch him ... We want to know where he is and we want to know whom he may or may not divulge state secrets."

Vanunu will not be allowed to travel abroad for at least a year, speak with foreigners or approach Israeli ports or borders. He also is barred from discussing his work at Israel's nuclear reactor. Vanunu was given a map of Israel marking the areas off-limits to him, the Defense Ministry said.

Defense Ministry spokeswoman Rachel Niedak-Ashkenazi said security services have confiscated several tapes and notebooks with Vanunu's writings. In Hebrew and English, Vanunu wrote a detailed account of places, processes and areas of the nuclear reactor, she said, adding that he has an "excellent memory."

"It was a lot more than a personal diary. To us this showed an intention and ability to make future use of it," Niedak-Ashkenazi said.

Vanunu said the papers were personal and had been written in 1991.

Vanunu's family and Yoav Loeff, of the Association for Civil Rights in Israel (search), which is representing the nuclear spy, have said they are concerned about his safety.

But Lapid said no precautions or special security measures are planned. "He's surrounded by at least 100 radicals who are worshipping him so I'm sure they'll take care of his safety," he said.

Vanunu will live in a luxury apartment complex in Jaffa, an old seaport and today part of Tel Aviv. Jaffa has both Arab and Jewish residents. Vanunu, who was raised as an Orthodox Jew, converted to Christianity in the mid-1980s.

The Andromeda Hill complex has 170 apartments, and tenants include both wealthy foreigners and local residents. It was unclear who is paying for Vanunu's apartment.

Richard Caseby, managing editor of the Sunday Times, said the newspaper was giving Vanunu "some assistance," but declined to elaborate. He said Vanunu was not paid for the original story.