A broad spectrum of U.S. religious groups — Christian, Jewish and Muslim — are condemning killings at a Sikh temple in Wisconsin that authorities described as an act of “domestic terrorism.”

The gunman, Wade Michael Page, a 40-year-old U.S. Army veteran, killed six people and injured three others Aug. 5 at the Sikh Temple of Wisconsin before being shot and killed by police. The temple is located in Oak Creek, a suburb of Milwaukee.

The Southern Poverty Law Center, which monitors hate groups in the U.S., described Page as a “frustrated neo-Nazi” who had led a racist white-power group.

Kathryn Lohre, president of the National Council of Churches, said in a statement that the NCC and its member churches “stand in solidarity with our Sikh brothers and sisters in this frightening time.”

Antonios Kireopoulos, the NCC’s associate general secretary who oversees the council’s interfaith work, said: “While it is difficult to know what was in the mind of the attacker, it would seem that it was the same mix of fear, ignorance, and bigotry that fuels all violence against individuals or communities of faith.

“It is our prayer that such acts of terrorism — for they are in fact terrorist acts — become less and less frequent, and indeed come to an end, as our society becomes more and more vigilant in educating one another on what it truly means to live as neighbors of one another.”

Indian Prime Minister Manmohan Singh, himself a Sikh, expressed shock and urged U.S. authorities to ensure such violent acts are not repeated. He said the fact that the shooting was “targeted at a religious place” made it even more painful.

The Council on American-Islamic Relations said American Muslims “stand with their Sikh brothers and sisters.” It added, “we condemn this senseless act of violence, pray for those who were killed or injured and offer sincere condolences to their loved ones.”

B’nai B’rith International, the Jewish humanitarian, human rights and advocacy organization, used similar language, saying: “We stand in solidarity with the Sikh community as our thoughts and prayers go to the victims and their families.”

The NCC noted that Sikhs — whose religion emphasizes devotion to peace — originated in the Punjab region of India in the 15th century. There are about 1.3 million Sikhs in the U.S. and Canada, and nearly 20 million in India.

Since the Sept. 11, 2001, terrorist attacks, Sikh men, who wear turbans and beards, have sometimes been confused with Muslims, authorities said. As a result, they have been targets of hate crimes.

Additional reporting was contributed by Anto Akkara in India.