"For the past three years your words and your policies have emboldened a growing white nationalist movement. You yourself called the murderer evil, but yesterday's violence is the direct culmination of your influence," the open letter said.

It called on Trump to "fully denounce white nationalism," to "stop targeting and endangering all minorities," to "cease your assault on immigrants and refugees" and to "commit yourself to compassionate democratic policies that recognize the dignity of all of us."

Until he does so, Trump -- who has announced his intent to visit Pittsburgh -- is not welcome in the city, the letter said.

The shooting, which has sparked an outpouring of grief and shock from American Jews, came just days after a pipe bomb was sent to prominent Jewish philanthropist George Soros, who has been the target of what many see as anti-Semitic conspiracy theories.

Such conspiracy theories, which accuse Jews of dominating government and finance, are rife among the so-called "alt-right" movement, which is supportive of Trump and has gained significant influence in recent years, including through the president's former chief strategist Steve Bannon.