SAN FRANCISCO, Jan. 28 (Xinhua) -- A white supremacist group claimed responsibility Sunday for an anti-immigration stunt in San Francisco on the U.S. western coast.

The neo-Nazi activist organization, Identity Evropa, admitted on Twitter that it hang a huge banner mocking San Francisco's policy on undocumented immigrants over the Yerba Buena Island tunnel that links the island in the northeast with downtown San Francisco.

The sign read "Danger" in red letters and "Sanctuary City Ahead" with a skull and crossbones on either side of the poster.

"PUBLIC SERVICE ANNOUNCEMENT FROM IDENTITY EVROPA

San Francisco is a dangerous sanctuary city where the law does not apply to illegal invaders.

Enter at your own risk!" Evropa tweeted, also posting photos of the sign on its Twitter account.

The huge banner was removed shortly on Sunday morning.

The group, founded in March 2016, is a white supremacist organization and designated as a hate group by the Southern Poverty Law Center (SPLC).

It said on its website that its members were composed of "a generation of awakened Europeans who have discovered that we are part of the great peoples, history, and civilization that flowed from the European continent."

The SPLC believed that group is recruiting college-aged white students to campaign for white interests.