An arson suspect was arrested on Sunday afternoon, hours after the Pennsylvania governor's official residence was blazed and partly damaged in the state's capital city of Harrisburg, said Pennsylvania State Police.

The suspect was identified as Cody Balmer, a 38-year-old man from Harrisburg, Pennsylvania State Police Colonel Christopher Paris told a press conference.

The suspect hopped over a fence around the governor's residence and forcibly entered the building before setting it on fire early Sunday morning, according to the state police.

The attack was "targeted" but its specific motive is still unknown, Pennsylvania Governor Josh Shapiro said at the conference.

Shapiro said that he, his wife, their four children, two dogs and another family that had celebrated Passover on Saturday were inside the home when they "woke up to bangs on the door from Pennsylvania State Police" around 2:00 am (0600 GMT) on Sunday.

Balmer will face charges including attempted murder, terrorism, arson, and aggravated assault against an enumerated person, said Dauphin County District Attorney Francis Chardo at the press conference.

No one was injured by the fire, but parts of the residence sustained a "significant amount of damage", said the state police in a statement earlier on Sunday.

Shapiro, 51, a Democrat, is considered a potential contender in the 2028 U.S. presidential race.