Jewish groups have offered messages of condolence and called for interfaith understanding in the wake of the fatal attack on a Sikh temple in Wisconsin.

Six people were left dead after a man, identified by investigators as a known white supremacist, went on a shooting spree on Sunday afternoon.

The attacker, Wade Michael Page, was killed by a police officer during the attack, which left several others with serious injuries.

It has now emerged that he was discharged from the army in 1998 and was known to the hate monitor , the Southern Poverty Law Centre as a "frustrated neo-Nazi".

"We are deeply shocked by this heinous act of violence against peaceful innocent Americans , targeted at their house of worship, apparently singled out because of their faith and appearance that makes them appear different from other Americans," said Abraham Foxman, national director of the Ant-Defamation League, who described the shooting as a hate crime. "This attack is another gruesome reminder that bigotry and hate against those whose religion makes them "different or "other" can have deadly consequences."

The American Jewish Committee and the Union of Orthodox Jewish Congregations of America also expressed their sympathies with the families of the victims.

"We express our grave concern over a place of religious worship being violated by a heinous act of violence," said a spokesman for the union.

The AJC's executive director, David Harris, added: "We fully share with our friends in the Sikh community outrage over this inhuman assault, and cannot begin to fathom why any gunman would target their Wisconsin temple."

The campaign director of interfaith group Shoulder to Shoulder added: "The tragedy in Milwaukee shows painfully the need for Americans of all faiths to learn about one another and embrace the diverse religious tapestry of the United States."