Prime Minister Ehud Olmert vowed on Monday to fight violent "incitement" by Israeli groups opposed to his efforts to negotiate with the Palestinians and said he was ready to make "painful concessions" to secure peace.

His speech, heavy with memories of violence within Israeli society, was a reaction to displays of hostility that marked Sunday's 12th anniversary of the assassination of Prime Minister Yitzhak Rabin, who was shot by a Jew angry at his peace efforts.

Soccer stadium chants, posters showing Israel's president in an Arab headdress, celebrations of the birth of a son to Rabin's jailed killer and a torchlight rally during a visit by U.S. Secretary of State Condoleezza Rice triggered comment in some newspapers about a resurgence of right-wing radicalism.

"We will fight these phenomena that incite violence and will eradicate them," said Olmert, who denounced jeering right-wing fans of his own hometown soccer team as "brutish and violent".

"Peace is achieved through concessions. We all know that," said Olmert, once a hawkish member of the right-wing Likud party who now leads a centrist coalition that has embarked on the most detailed peace talks with Palestinians in several years. Surrounded as ever by heavy security, the prime minister was addressing a business conference in Jerusalem.

Several hundred marchers in Jerusalem on Sunday said they opposed any handover of parts of the city to a Palestinian state. Many also oppose the creation of any such Arab state on land they believe was given to the Jews by God.

On the same day, posters went up around Jerusalem depicting President Shimon Peres, Rabin's partner in 1990s peace moves, wearing a headdress in the style of late Palestinian leader Yasser Arafat. Similar portrayals of Rabin appeared shortly before he was gunned down on Nov. 4, 1995.

Rabin's killer, Yigal Amir, was allowed to hold the ritual circumcision of his first child in prison on Sunday, angering Israeli liberals who had campaigned against the right to conjugal visits for Amir. He remains a hero to the far right.

Olmert also lashed out at fans of his own favourite soccer team, Betar Jerusalem, who booed during a minute's silence for Rabin before a match on Sunday. Some Betar fans, who have a reputation for hardline nationalism, shouted insults.

"Contrary to all that those provocateurs are saying, the state of Israel will be ready to make numerous and painful concessions to change reality in the region," Olmert said.

Israel's mass-selling Yedioth Ahronot daily commented: "A new era is beginning, a stormier, dramatic and -- as we saw yesterday -- also an ugly one. And ugly is an understatement."

Maariv newspaper headlined: "Incitement is back." (Editing by Alastair Macdonald)