Republican Eric Greitens, who is seeking a U.S. Senate seat in Missouri, released a campaign ad on Monday depicting him and a group of armed men going hunting for "RINOS," or "Republicans in name only" - prompting social media platforms to flag or take down the video.

"I'm Eric Greitens, Navy SEAL, and today, we're going RINO hunting," the 48-year-old former Missouri governor says at the start of the ad, racking a shotgun.

Greitens and a team dressed in military gear then break down the door of a house, throw what appears to be a stun grenade inside and storm into the building.

"Join the MAGA crew," Greitens tells the camera, referring to Republican former President Donald Trump's slogan, Make America Great Again. "Get a RINO hunting permit. There's no bagging limit, no tagging limit and it doesn't expire until we save our country."

The ad was released amid a national debate over gun violence following the May 24 Texas elementary school massacre that left 19 students and two teachers dead and the racially motivated killing of 10 Black people in Buffalo, New York, on May 14.

Twitter flagged the ad, saying it violated the social media platform's rules about abusive behavior. Facebook took it down, prompting Greitens to post a Facebook message criticizing the platform for removing it and vowing to take on "Big Tech" if elected.

Greitens' campaign did not immediately respond to a request for comment.

Missouri's primary election is scheduled for Aug. 2. Greitens is one of many Republicans seeking their party's nomination, including U.S. Representative Vicky Hartzler and state Attorney General Eric Schmitt, for the seat held by retiring Republican Senator Roy Blunt.

The ad also drew immediate condemnation, including from some Republicans who said Greitens was encouraging political violence.

"Every R should denounce," Republican former congresswoman Barbara Comstock of Virginia said on Twitter. "This is such a sick and dangerous ad."

Greitens has previously come under pressure from some Republicans to drop out of the race after his former wife accused him of abusive behavior. He has denied any wrongdoing.

He resigned as governor in 2018 after being accused of photographing a woman naked and threatening to release it if she went public about their relationship, though he denied the allegations.

Adam Kinzinger, a Republican congressman who on Sunday posted a letter addressed to his wife that threatened to kill their whole family, called Greitens a "very bad man" on Twitter.

Kinzinger, who has broken with his party over Trump, is a member of the U.S. House committee investigating the Jan. 6, 2021, invasion of the Capitol by a group of Trump supporters trying to stop Congress from certifying Democrat Joe Biden's presidential election victory.