U.S. House Speaker Nancy Pelosi’s husband, Paul, 82, has been hospitalised after he was brutally assaulted with a hammer by an intruder at his San Francisco residence early Friday.

The assailant, identified as David Wayne Depape, a 42-year-old man from Berkeley, broke into the Pelosi residence screaming “Where is Nancy?” Fox News quoted a law enforcement officer as saying. The Speaker at the time was in Washington D.C.

Using a hammer, Mr Depape had “violently assaulted” Mr Pelosi, before the police’s arrival.

The 82-year-old man suffered blunt force injuries to his head and body, sources familiar with the matter told The Associated Press.

Police officers, the first responders in the attack and who witnessed the assault, wrestled the hammer from Mr Depape and took him into custody in the early hours of Friday. They are yet to determine a motive for the assault.

“Early this morning, an assailant broke into the Pelosi residence in San Francisco and violently assaulted Mr Pelosi,” reads a statement by Drew Hammill, the Speaker’s spokesperson, issued on Friday. “The assailant is in custody and the motivation for the attack is under investigation.”

Although the speaker was not in town at the time of attack, the statement disclosed Mr Pelosi had been taken to a health facility, where he was “receiving excellent medical care.”

Reacting to the attack, The White House disclosed U.S. President Joe Biden “is praying for Paul Pelosi and for Speaker Pelosi’s whole family.”

Similarly, Capitol Police said the security unit would assist “the Federal Bureau of Investigation (FBI) and the San Francisco Police with a joint investigation into a break-in at the California home of the Speaker of the House of Representatives.”