According to Crimea news website, the assailants first tried to enter the mosque but failed to do so and then threw three Molotov cocktails inside and set the building ablaze.
Azhdar Ismailov, the Mufti of the mosque, said it was not the first time such an attack took place.
He said the place of worship had been set on fire in another attack seven months ago.
Ismailov hoped the assailants will be arrested and brought to justice.
The majority of Crimean population adheres to the Russian Orthodox Church, with the Crimean Tatars forming a Muslim minority.
Crimea declared independence from Ukraine on March 17, 2014, and formally applied to become part of Russia following a referendum a day earlier, in which 96.8 percent of Crimean residents voted in favor of the secession.
http://iqna.ir/fa/news/3526637