A rash of anti-Chinese fliers left at San Francisco businesses earlier this month has rattled the Asian community, evoking concern that hate crimes are becoming more commonplace.

Jewish leaders quickly called for solidarity with the local Chinese community following the incidents.

They drew comparisons with last month's synagogue arsons in Sacramento and the shootings directed at blacks, Jews and Asians over the Fourth of July weekend in Indiana and Illinois.

The anti-Chinese hate mail "has to be seen within an atmosphere that has unfortunately resulted in several very visible hate crimes," said Rabbi Doug Kahn, executive director of San Francisco's Jewish Community Relations Council.

At a press conference last week, Kahn stressed that the incident showed "hate crimes know no boundaries."

The press conference, he said, "was as much directed toward members of the Chinese-American community who may have received these vicious hate pieces, to encourage them to come forward, as it was toward the broader public."

The two-page hate letter was stuffed into mailbox slots at Chinese-owned businesses in the Richmond, Sunset and Chinatown districts earlier this month..

The typed letter, replete with spelling and grammar errors, lashed out at the Chinese for "ripp[ing] off" the "white people." The letter also calls for retaliation.

"Stop the yellow scum," the letter said. "Do something today for us white people, get them where it hurts. Rip them off. Spit on them, flip them off, anything, but do something…Get them first and get them good! They will do it to you!"

The S.F.-based Chinese for Affirmative Action said that anyone who has received the letter should contact the police.

"What we are most concerned about is the timing," said Diane Chin, director of the organization.

Chin added that the letters also came at "a time when the national debate has focused yet again on the Asian community as foreigners involved in illegal espionage and campaign contributions."

Chin said she was warmed by the rapid response, particularly from the local Jewish and Latino communities. "We really appreciated those calls."

Kahn said that people "as a whole need to speak out against hate crime against any group.

"It affects everyone because they are a potential target, no matter their religion or color of skin."