President Donald Trump called Robert Bowles "pure evil" after he killed at least 11 when he opened fire a Pittsburgh's Tree of Life congregation on Saturday.

"This wicked act of mass murder is pure evil [...] You wouldn't think this would be possible in this day and age, but we just don't seem to learn from the past," Trump said during a rally in Indianapolis.

"There must be no tolerance for anti-Semitism in America or for any form of religious or racial hatred or prejudice"

"We are praying for the families of the victims and our hearts go out to the wounded law enforcement officers in Pittsburgh"