The Israel branch of the Simon Wiesenthal Center on Sunday gave Germany and the United States top marks in its annual report on efforts to hunt down Nazi war criminals.

The organization, run by Nazi hunter Efraim Zuroff, placed both countries in its Category A, of states which “have taken all reasonable measures to identify the potential suspected Nazi war criminals in the country in order to maximize investigation and prosecution and have achieved notable results during the period under review.”

It specifically praised Germany for implementing a legal strategy that “paves the way for the conviction of practically any person who served either in a Nazi death camp or in the Einsatzgruppen (mobile killing units).”

It was published as Israel prepared to observe Holocaust Remembrance Day from sundown, with the entire country coming to a standstill for two minutes of silence on Monday to remember the six million Jews killed during the Holocaust in World War II.

The survey gave Argentina, Brazil, Costa Rica, the Czech Republic, Finland, Serbia, Slovakia and Slovenia an E, the grade given to countries where “no practical steps have been taken to uncover new cases.”

At the bottom of the rankings, with an ‘X,’ were Belarus, Belgium, Bolivia, Bosnia-Herzegovina, Chile, Colombia, Denmark, France, Greece, Luxembourg, New Zealand, Netherlands, Paraguay, Russia, Spain, Ukraine and Uruguay.

They “did not respond to the questionnaire, but clearly did not take any action whatsoever to investigate suspected Nazi war criminals during the period under review,” the report said.

A separate report on anti-Semitism published Sunday by Tel Aviv University registered a drop in violent attacks on Jews worldwide.

“The year 2013 witnessed 554 registered violent anti-Semitic acts…or direct threats against Jewish persons or institutions such as synagogues, community centers, schools, cemeteries, monuments as well as private property.”

It said that was down from 686 incidents the previous year.

It said that the country with the highest number of recorded events in 2013 was France with 116, compared to 200 in 2012 and 114 the year before.