Israeli Prime Minister Ehud Olmert, right, addresses the opening ceremony of the annual Holocaust Remembrance Day on Sunday at Yad Vashem Holocaust Memorial in Jerusalem. Israel will commemorate the country's annual Holocaust Remembrance Day from sundown Sunday to sundown today. Around 280,000 Holocaust survivors live in Israel.

Jerusalem ? The Vatican’s ambassador to Israel attended a Holocaust memorial service Sunday, reversing an earlier decision to boycott the event that threatened to upset fragile ties between Israel and the Holy See.

Monsignor Antonio Franco said last week he would skip the ceremony at Yad Vashem Holocaust memorial marking the beginning of Israel’s annual Holocaust Remembrance Day because Catholics were offended by a caption at the museum describing the wartime conduct of Pope Pius XII.

The caption next to the picture of Pius reads, “Even when reports about the murder of Jews reached the Vatican, the pope did not protest,” refusing to sign a 1942 Allied condemnation of the massacre of Jews.

Pius “maintained his neutral position” with two exceptions – appeals he made to the rulers of Hungary and Slovakia toward the end of the war, the caption says. It also criticizes “his silence and absence of guidelines.”

Israel and the Vatican established diplomatic relations in 1993 following hundreds of years of painful relations between Catholics and Jews. Many sensitive issues remain unresolved, including the Vatican’s actions during the Nazi genocide of Jews.

The Vatican has struggled to defend its wartime pope as it pushes his sainthood cause, insisting that Pius spearheaded discreet diplomacy that saved thousands of Jews.

The disputed photo caption first appeared in 2005, when Yad Vashem opened its new museum.

Shortly after, the previous Vatican ambassador asked that it be changed.

But Yad Vashem has not done so, insisting its research on the pope’s role was accurate.

The memorial service is traditionally attended by all foreign ambassadors to Israel or their representatives. Had Franco stated away, Yad Vashem said it would have been the first time a foreign emissary deliberately skipped the ceremony.

Holocaust Remembrance Day, which commemorates the 6 million Jews killed by the Nazis during World War II, is observed from sundown Sunday to sundown today with memorial ceremonies, somber music on the radio and historical documentaries and movies on national television.

Today at 10 a.m., sirens will wail throughout Israel for two minutes with Israelis standing silently to remember the victims.

Yad Vashem spokeswoman Iris Rosenberg said the memorial appreciated Franco’s decision, calling it “the right thing to do.”

“Yad Vashem believes that it was inappropriate to link an issue of historical research with commemoration of the victims of the Holocaust,” she said.

Yad Vashem has said it would be ready to re-examine Pius XII’s conduct during the Holocaust if the Vatican opened its World War II-era archives to the museum’s research staff and new material emerged. Despite frequent requests from Holocaust researchers, the Vatican has denied access to major parts of its archives, including wartime papers.