JEDWABNE, Poland — The rough stone monument in this farming village shocks with its terse language: "Site of a massacre of Jews. Gestapo and Nazi soldiers burned 1,600 people."

But the Polish words etched into the small gray stone belie an even more horrible truth. Communist officials who had it erected surely knew. So did most of the villagers, though they rarely spoke of it.

Now all Poland is being jolted awake to the awful reality: The Jews of Jedwabne were locked in a barn and burned to death on July 10, 1941, not by Nazis, but by their neighbors — fellow Poles.

Grim details laid out in "Neighbors," a book by Polish emigre Jan Tomasz Gross, have helped blow the cover off decades of communist propaganda and forced Poles into sober reassessment of their self-image as victims — and never collaborators — in Nazi oppression.

Poland's president is offering an apology, and the head of its Roman Catholic Church plans special joint prayers of Catholics and Jews.

Jedwabne (pronounced Yed-VAB-neh) was not the only wartime pogrom by Poles, but it was the biggest — and perhaps now the best documented. Poland's reluctance to confront the truth has nurtured among many Jews an image of Polish complicity in Nazi horrors, in stark contrast to a national memory that emphasizes heroic resistance and well-documented risks Poles took to shelter Jews.

While historians generally accept that Poles were at least in part responsible for the Jedwabne horror, there has never been a credible investigation, just a speedy two-day trial in 1949. "Neighbors," based in part on witness accounts from Jewish survivors and non-Jewish townspeople, is the first thorough treatment of the massacre.

Stanislaw Michalowski, 48, head of the village council, said he first heard the story about villagers massacring Jews when he was 8 but never gave it much thought. Then he read "Neighbors." Now he says he is "not the same man."

"We were raised in the conviction that we, Poles, were clean during the war, that atrocities had nothing to do with us," he said. "It's morally crushing to realize what happened."

Gross writes that when Nazi commanders moved into the eastern Polish village, they "easily reached agreement" with town officials on what to do about the Jews. Hundreds, including women and children, were soon brought to the town square. They were beaten with clubs and stones, then herded into a barn, which was locked and set ablaze.

"Had Jedwabne not been seized by Germans, the Jedwabne Jews would not have been murdered by their neighbors," Gross writes. "But the direct participation of Germans was limited mostly to taking pictures and filming.

"The 1,600 Jedwabne Jews were murdered not by the Nazis or Soviets but the society."

Acceptance is difficult for a nation that lost 6.5 million citizens, including 3 million Polish Jews, under Nazi occupation.

At the same time, the devoutly Roman Catholic nation has been harshly criticized by international Jewish groups for refusing to admit any complicity in atrocities.

"The investigation proves that all efforts to deny that there was deep-rooted anti-Semitism in Poland were futile, and that it influenced what took place," said Yisrael Gutman, a former head of research at Yad Vashem, Israel's Holocaust institute. He also expressed concern that the facts had been suppressed in Polish society for decades, saying: "This investigation comes late."

Uproar over "Neighbors" has been building steadily since a few thousand copies were published last spring and the issue is now being aired abroad. Gross published a long account of the massacre in last week's New Yorker magazine, and an English-language version of his book is being released in April by Princeton University Press.

"I deeply believe that getting to know what happened in Jedwabne will become a breakthrough in our historical myths and will help us clean our conscience," said Gross, a Jew who left Poland after the anti-Semitic propaganda campaigns of 1968 and now teaches at New York University.

"Such mass murder concerns us all," he said in an interview with The Associated Press during a visit to Poland.

Similar debates have flared since the 1989 collapse of communist rule allowed Poles to begin filling in censored pages of their history. But "Neighbors" seems to have struck a national nerve.

"Gross has forced us to change our opinions on Poles' attitudes during the war, and that is his undeniable contribution," said historian Tomasz Szarota, who has written extensively on the Nazi occupation.

President Aleksander Kwasniewski, an ex-communist, said last week he will issue a formal apology for Jedwabne on the 60th anniversary of the massacre in July, and change the inscription on the 1963 monument. But he rejects any notion that Poland accept collective responsibility.

"The world must hear our assessment of that event," Kwasniewski said. "We have to build a normal future inside Poland and with our foreign partners, with Jews all over the world and with Israel."

The leader of Poland's Roman Catholic Church, Cardinal Jozef Glemp, also acknowledged the involvement of Poles in the Jedwabne massacre, and plans to offer joint prayers for Poles and Jews on the anniversary.

Meanwhile, Poland's new National Remembrance Institute has opened its own investigation and is interviewing witnesses, which could lead to a trial of any participants still living. A communist-era court convicted 12 villagers of collaborating with the Nazis after a speedy trial and sentenced them to terms ranging from 8 to 15 years. One death sentence was later commuted.

"I will do everything so that this dark page in our history is not kept secret," the institute's chairman, Leon Kieres, said on Polish radio. "As a Pole, I can't shake off the blame for what has happened."

Many questions remain. Some of the institute's historians say Gross drew hasty conclusions without, for example, explaining the extent to which the local population was bullied by the Germans into collaborating.

"The fact that Poles were murdering is undeniable," historian Szarota said. "But to understand Jedwabne we would have to know whether the murder was done spontaneously by the local residents with the agreement of the Nazi soldiers, or whether it was done by scum instigated by Germans who had sent a police battalion to clean the town of Jews."

Another troubling question: Why did it happen in Jedwabne, where there is no prior evidence of anti-Semitism or civic unrest?

Until Hitler declared war on the Soviet Union, the Soviets controlled eastern Poland. Many Polish Jews felt safer under the Soviets than under the Nazis, and some have suggested the Jedwabne villagers acted out of revenge for what they saw as Jewish complicity with the Soviets.

Already, the Krakow-based Organization of Veterans and Independence Fighters has complained that Kwasniewski shouldn't speak of apologies before Polish complicity is verified.

A Jedwabne social committee formed to protect the town's reputation also has complained that published accounts of the massacre are biased and incomplete.

"Nothing has to be changed on that monument," said the Catholic parish priest in Jedwabne, Edward Orlowski. "Germans forced those people to do it. Many of them were hooligans, but they happen to be in every society. Why dig that thing up? Why release the ghosts of the past?"