WASHINGTON: A joint investigation is underway after US House Speaker Nancy Pelosi's husband was attacked during a home break-in early Friday morning, Xinhua reported.

The US Capitol Police said in a press release that they are assisting the Federal Bureau of Investigation and the San Francisco Police with a joint investigation into the incident.

The speaker's husband, Paul Pelosi, was "violently assaulted" with a hammer by an individual who broke into their home in San Francisco, California, according to a spokesperson.

The assailant is in custody. Paul Pelosi, 82, "underwent surgery to repair a skull fracture and serious injuries to his right arm and hands", at Zuckerberg San Francisco General Hospital, the spokesperson said in a statement, and he is expected to make a full recovery.

Nancy Pelosi, second in the line of succession to the US presidency, was in Washington, D.C., with her protective detail at the time of the break-in, the Capitol Police said.

David DePape, 42, has been identified by police as the suspect in the assault on Paul Pelosi and will be booked on charges including attempted homicide, assault, and elder abuse.

San Francisco Police Chief William Scott told reporters that the motive for the attack was still being determined.

The White House said in a statement on Friday that US President Joe Biden had called Nancy Pelosi to "express his support after this horrible attack".

Biden "continues to condemn all violence", the White House statement said.

-- BERNAMA