A racist manifesto that appears to be the work of Dylann Roof, the suspected killer of nine African-Americans in a South Carolina church, calls for the destruction of "Jewish identity".

The text, which surfaced online in the aftermath of the bloody rampage at a historic black church in Charleston last week, was being investigated by authorities to establish whether it was penned by Roof.

In a discussion about white supremacy, its author writes: "I found out about the Jewish problem and other issues facing our race."

The 2,444-word document, which is riddled with typos, dedicates an entire section to jews, suggesting "the issues with Jews is not their blood, but their identity… If we could somehow destroy the jewish identity, then they wouldnt cause much of a problem."

The cold-blooded attack has stirred soul-searching in a nation already gripped by a wave of racially charged protests that have followed the killing of black men by police officers.

In the online text, which has been taken down, the author appears to blame that unrest on Jews by referring to "the Jewish agitation of the black race".