WARSAW, Poland (CNS) -- Polish Catholic leaders condemned a new wave of anti-Semitism in the country amid tension over a government-backed law on responsibility for the Holocaust.

Archbishop Wojciech Polak of Gniezno, Poland's Catholic primate, called anti-Semitism "a moral evil and a sin," saying attempts to divide people or pit them against each other "in a nationalistic context should be totally censured."

"Any political activity which causes divisions, prejudices or tribal thinking is dangerous," he said after the Polish bishops' conference discussed the controversy during their plenary, which ended March 15.

Archbishop Stanislaw Gadecki of Poznan, president of the Polish bishops' conference, said hostility belonged "neither to Christian nature nor to the nature of Judaism." He urged prayers to ensure "the great good achieved by common efforts of Poles and Jews" was not squandered.

"We hear of an increase in aggressive attitudes among both Poles and Jews, who've begun to fear for their presence in Poland and speak very harshly about Poles," Archbishop Gadecki told Poland's Catholic Information Agency, KAI, March 14.

"We need a spirit of peace to mitigate these extreme positions and show there's more uniting than dividing us," he said.

More than 6 million Polish citizens, half of them Jews, were killed during Poland's 1939-1945 occupation by Nazi Germany. Polish officials have long objected to accusations of Polish complicity in the Holocaust.

In place since March 1, the law imposes up to three years in jail for anyone who "publicly and against the facts attributes to the Polish nation or Polish state responsibility or co-responsibility for Nazi crimes," or "flagrantly reduces in any way the responsibility of the real perpetrators."

However, the law was condemned as "baseless" by Israel Prime Minister Benjamin Netanyahu as well as the Jerusalem-based Yad Vashem Memorial Institute, which warned that it would impede Holocaust research and debate.

In late February, Poland's chief rabbi joined leading Jewish organizations in expressing outrage over a "growing wave of intolerance, xenophobia and anti-Semitism" that had found its way into public media outlets and statements by members of parliament and state officials. They warned that condemnations by Polish leaders would "ring empty" without action "to stop the spread of evil."

In a March 14 statement, the Polish bishops said St. John Paul II had urged Christian nations to "uproot from their mentality all unjust prejudices about Jews and other symptoms of anti-Semitism."

They added that Poles had shown "heroic attitudes" in helping persecuted Jews during World War II and called for continued dialogue "in this spirit."

Addressing a Holocaust commemoration rally in Krakow March 11, Cardinal Stanislaw Dziwisz urged Polish Catholics to "witness to faith" by remembering how they had helped "neighbors in need," as well as "through being able to reckon with what we failed to do."

However, Archbishop Waclaw Depo of Czestochowa told Catholics during a March 8 Mass efforts were underway to "alter historical truth," by turning Poles "into executioners," when they were in reality "a nation of sacrifice and suffering."

The chairman of the Polish church's Commission for Dialogue with Judaism, Auxiliary Bishop Rafal Markowski of Warsaw, told KAI he had warned the bishops' conference of the dangers of "turning a very emotional political and media debate" against people.

"In the recent past, we've felt we were building trust and cooperation by jointly cultivating key anniversaries and visiting places linked with the Holocaust," the bishop said.

"I'm afraid this achievement could now be wrecked, and I fear for those small village and parish communities where groups of people have cared for Jewish cemeteries and tried to commemorate the Jewish presence," he said. "I fear they'll now face dangerous pressure."