Within an hour of the Boston Marathon explosions, conservative columnist Erik Rush, who writes for WND and is a frequent Fox News contributor, took to Twitter, blaming the attack on Muslims.

He tweeted: Everybody do the National Security Ankle Grab! Let's bring more Saudis in without screening them! C'mon! #bostonmarathon

A Twitter user immediately tweeted back at Rush, saying: “Sweet God. Are you ALREADY BLAMING MUSLIMS??” to which Rush responded: “Yes, they’re evil. Let’s kill them all.”

Right Wing Watch, a group that works to shed light on right-wing organizations and expose the risks of their extreme and intolerant agendas, reported the story with the original tweets, which are no longer on Rush’s Twitter account. The controversial columnist, who said his comments were sarcastic, was later called out on his supposed backtracking, which he denied.

And it doesn’t stop there. The tweets keep going back and forth between Rush and his detractors, whom he taunts, tweeting:

You can see all of Rush’s tweets on his Twitter page.