Authorities were alerted to the letter Thursday night after someone at the Evergreen Islamic Center on Ruby Avenue found it.
Investigators are treating it as a "hate-motivated incident,” said Sgt. Enrique Garcia, spokesman for the San Jose Police Department.
The letter called the recipients "children of Satan” and "vile and filthy people,” according to KNTV, which obtained a copy of the message.
Members of the mosque referred inquiries to the president of the center’s board of directors, who couldn’t immediately be reached.
"There’s a new sheriff in town — President Donald Trump,” the letter said. "He’s going to cleanse America and make it shine again. And, he’s going to start with you Muslims.”
"You Muslims would be wise to pack your bags,” the note continued.
Source: SF Gate