Conservatives are slamming Michael Moore and rallying around the Oscar-nominated movie “American Sniper” after the liberal filmmaker said that snipers are "cowards."

In a Sunday tweet, Moore, the director behind “Fahrenheit 9/11” and “Bowling for Columbine”, wrote to his nearly two million followers on Twitter:

Moore’s tweet set off a firestorm on the right, with many considering it an attack on the military and the just-released movie, “American Sniper.” The film, directed by Clint Eastwood, stars Bradley Cooper as real-life Navy SEAL Chris Kyle, the most deadly sniper in American military history.

The tweet is a "despicable attack," according to Move America Forward, a pro-military political action group.

“We want you to go see this film and share in the celebration of what it stands for,” the group wrote in an email to supporters, offering gift certificates to donors to go see the movie.

It’s not the first time Move America Forward has clashed with Moore. The PAC started a letter-writing campaign to urge movie theaters not to screen his 2004 documentary, “Fahrenheit 9/11,” calling it an “al Qaeda training video.”

Others, including 2012 GOP presidential candidate Newt Gingrich, also jumped on Moore’s comments:

Moore clarified his remarks in a Monday Facebook post, saying he "didn't say a word about 'American Sniper'" in his Twitter messages, and tweeted:

“American Sniper” set records at the box office after opening in wide release on Friday, reportedly pulling in more than $105 million during the four-day holiday weekend.