House Republicans’ campaign committee released a new ad attacking billionaire Democratic donor George Soros as a “radical” on Wednesday, just two days after a bomb was found in Soros’s mailbox.

The new ad from the National Republican Campaign Committee’s independent expenditure arm, entitled “Owes,” is aimed at Minnesota House candidate Dan Feehan, who is locked in a close contest with Republican Jim Hagedorn.

Soros is portrayed as one of the shadowy forces who “own” Feehan, because of donations from a Soros foundation to the Center for a New American Security, where Feehan is a fellow.

“Look at who finances Dan Feehan’s employer,” the ad’s narrator reads. “Radical George Soros, Wall Street’s biggest banks, a crooked lobbyist tied to Pelosi.”

The ad comes two days after an explosive device was discovered in a mailbox at one of Soros’s homes. The bomb appeared to have been hand-delivered, according to the New York Times. The paper reported that the bomb it was similar to other devices discovered Wednesday that were intended for Barack Obama, Hillary Clinton, and CNN’s New York office.

Soros’s donations to liberal causes have made him a frequent target for Republican attacks and conspiracy theories over the last decade.

The ad isn’t the first time the NRCC has painted Soros as a shadowy force behind Feehan. Last week, the NRCC released an ad portraying Soros with stacks of money.

In a statement on the new ad, NRCC spokesman Matt Gorman described the ad as “entirely factual.”

"Attempted violence against Mr. Soros or anyone else is repugnant and we condemn it in the strongest possible terms,” Gorman said. “This ad is entirely factual and is in no way a personal attack."