Jewish officials say a fire was set at the largest yeshiva in Russia as the faithful were gathered there before the start of the Jewish Passover holiday.
No one was reported injured in the April 19 fire at the Torat Chaim school in an eastern Moscow suburb.
Olga Esaulova, a spokeswoman for Moscow's chief rabbi, was quoted by the Interfax news agency as saying the fire was set in a storage area for kosher meat and that swastikas were drawn at the yeshiva's entrance.
The fact that the arson was committed on the eve of one of the most significant Jewish holidays was outrageous, Esaulova said.
She expressed hope that the authorities will find the offenders.
There were about 60 students, rabbis, and guests in the building at the time, the state news agency RIA Novosti reported.