After pipe bombs addressed to a series of prominent Democratic figures were discovered on Wednesday, officials said Thursday morning they had found packages with explosive devices addressed to former Vice President Joe Biden and the actor Robert De Niro.

Authorities reported that the package addressed to Biden appeared to match those containing bombs sent to well-known Democrats, including Hillary Clinton, Barack Obama, and George Soros. The package, like the one sent to former Attorney General Eric Holder, was incorrectly addressed and returned to sender. Authorities intercepted the package at a facility in Delaware, according to the Associated Press. Later, a second, similar package addressed to Biden was found at a separate postal facility in Delaware, the AP reported.

Breaking: Pic of suspected bomb package sent to Former Vice President Joe Biden in postal facility in Delaware. It appears to not have been delivered because of “postage due”as at least one reason along with wrong address. Same return address label as others sent. @FOX29philly pic.twitter.com/mB55K5Kn9X — Steve Keeley (@KeeleyFox29) October 25, 2018

Early on Thursday morning, a package was also reported on a block in Manhattan where De Niro’s production company, Tribeca Enterprises, and connected restaurant, Tribeca Grill, are based. A law enforcement official told the New York Times that an X-ray confirmed it contained a device resembling a pipe bomb. Police safely removed the package.

pic of the package sent to DeNiro- @ShimonPro says that a former police officer who works in the building recognized that it looked like the packages sent/discovered yesterday, alerted authorities. pic.twitter.com/5Cp5PyXQEn — Elizabeth Landers (@ElizLanders) October 25, 2018

De Niro has been an outspoken critic of President Donald Trump. In June, at the Tony Awards, he gave a profanity-laden presentation directed at the president. “It’s no longer down with Trump,” he said, “but fuck Trump.”

Including the three reported Thursday, there have been 10 packages suspected of containing homemade bombs delivered to prominent Democrats this week.

Homemade bombs have been confirmed to have targeted Soros, Clinton, Obama, Holder, CNN’s New York offices (but addressed to former CIA Director John Brennan), and Rep. Maxine Waters. Most of the packages listed Rep. Debbie Wasserman Schultz, a former chairwoman of the Democratic National Committee, as the return address; when the package intended for Holder was redirected to the return address on the label, it was sent to her office in Sunrise, Florida, where it was intercepted. According to the FBI, investigators found two package bombs addressed to Waters on Wednesday night.

NBC News reported later Thursday afternoon that law enforcement officials have said some of the bombs were incapable of exploding. It is not yet known if that was intentional or resulted from a design flaw.

The bombs discovered this week came with manila envelopes, computer-printed address labels, six “forever” stamps, and return addresses with Wasserman Schultz’s name misspelled, according to the Washington Post. Law enforcement have described them as pipes stuffed with explosive materials and wrapped in electrical wire and tape. Authorities said Wednesday that at least some of them were also packed with shards of glass. According to the Post, law enforcement officials have said they believe at least two of them appear to have been hand-delivered.

Like those other packages, the ones addressed to De Niro and Biden reportedly listed Wasserman Schultz in the return address and had six American flag stamps, in two rows.

According to NBC News, an image of one of the explosive devices from the week appears to show a parody of an ISIS flag from a right-wing meme. The parody image replaces the Arabic characters with the silhouette of three women in high heels. The text, in English but imitation Arabic script, reads “Get ‘Er Done,” the catchphrase of comedian Larry the Cable Guy. That parody flag, created in 2014 by a right-wing parody site called World News Bureau, has been since shared around right-wing sites. An image of a person also appears to be on the side of the device, but that person has not been identified.

FBI Director Christopher Wray has asked the public to help catch what now appears to be a serial bomber, and he warned the public to avoid any suspicious packages. The FBI, along with the Secret Service, the NYPD, and other law enforcement agencies, are working to find the person or people behind the bombs.