Several of President-elect Donald Trump's cabinet and administration picks were targeted this week with actions including bomb threats and "swatting," a spokesperson for the transition team said on Wednesday.

The threats were made Tuesday night and Wednesday morning, and law enforcement acted quickly to ensure the safety of those targeted, spokesperson Karoline Leavitt said in a statement.

Elise Stefanik, a Republican US representative and Trump's choice to be US ambassador to the United Nations, and Lee Zeldin, a former Republican congressman who is Trump's pick to head the Environmental Protection Agency, both said in separate statements they had been the targets of bomb threats.

On Wednesday evening Pete Hegseth, Trump's nominee to be US defense secretary, said his family had been the target of a pipe bomb threat.

"This morning, a police officer arrived at our home - where our seven children were still sleeping. The officer notified my wife and I that they had received a credible pipe bomb threat targeting me and my family. We are all safe and the threat has been cleared," Hegseth said on X.

An FBI spokesperson said the bureau is aware of numerous bomb threats and swatting incidents targeting incoming administration nominees and appointees and is working with its law enforcement partners.

Swatting is the filing of false reports to police to induce a potentially heavy, armed response by officers at someone's home. Law enforcement experts see it as a form of intimidation or harassment that is increasingly being used to target prominent figures.

"We take all potential threats seriously, and as always, encourage members of the public to immediately report anything they consider suspicious to law enforcement," the FBI spokesperson said.

Stefanik said in a statement on Wednesday that she, her husband and their 3-year-old son were driving from Washington, D.C., to their family home in New York state when they were informed of the threat against their home.

Zeldin said he and his family also had been targeted.

"A pipe bomb threat targeting me and my family at our home today was sent in with a pro-Palestinian themed message," Zeldin said in a statement posted on X. "My family and I were not home at the time and are safe. We are working with law enforcement to learn more as this situation develops."

In Florida, the Okaloosa County Sheriff's Office said the home of a family member of former Republican congressman Matt Gaetz had also been targeted with a bomb threat.

Gaetz, Trump's first nominee to be US attorney general, withdrew his name from consideration on Nov. 21 after he faced opposition from US Senate Republicans over alleged sexual misconduct, which he denies.

"The mailbox was cleared and no devices were located. The immediate area was also searched with negative results," the sheriff's office said in a statement.

A White House spokesperson said Democratic US President Joe Biden had been briefed about the threats.

"The president and the administration unequivocally condemn threats of political violence," the spokesperson said.

The theats come months after Trump was wounded in an assassination attempt in Pennsylvania in July. In a separate incident in September, a man was charged with attempted assassination after allegedly positioning himself with a rifle outside one of Trump's Florida golf courses.