An alleged white supremacist has been arrested in an FBI sting after allegedly plotting to blow up a synagogue or poison those inside with arsenic.

Richard Holzer, 27, was accused of domestic terrorism after it was alleged he planned to target Temple Emanuel in Pueblo, Colorado.

He was said to have met undercover FBI agents at a motel, and the agents brought with them supposed pipe bombs and dynamite he planned to use on the synagogue.

According to an FBI affidavit Holzer told the undercover agents the explosives were "absolutely gorgeous" and said they should go ahead with the attack overnight to avoid police.

He said it was a "move for our race" and the synagogue was a "cancer," it was claimed.

The affidavit, filed in the US District Court in Colorado, said: “Holzer stated that he did not think anyone would be there [the synagogue], but that if they were, Holzer would not care because they would be Jews."