Russian investigators implicated Ukrainian nationalists were tied to the attack on a concert hall near Moscow claimed by ISIS-K, but the US says it is “nonsense propaganda.”

The United States on Thursday branded Russian officials “pretty good manure salesmen” after Moscow sought to link the attack on the Crocus City Hall music venue to “Ukrainian nationalists.”

“My uncle used to say that the best manure salesmen often carry their samples in their mouths. Russian officials seem to be pretty good manure salesmen,” White House national security spokesman John Kirby told reporters.

His remarks come after Russian investigators said they had evidence linking “Ukrainian nationalists” to last week’s attack on the concert hall on the outskirts of Moscow in which at least 143 people were killed.