One of Kamala Harris' campaign offices in Arizona was shot up overnight ... according to police.
The Harris campaign's Tempe office was damaged by gunfire just after midnight Tuesday ... only days before the Vice President is scheduled to return to Arizona for a big rally.
The Tempe Police Department says no one was inside the Harris campaign office when the shots were fired at the front windows, but cops say the incident is raising concerns about the safety of those working in the building.
In addition to Tuesday's shooting, police say the office's front windows were shot last week with what appears to be a BB or pellet gun ... and law enforcement is investigating both incidents.
Kamala's campaign reportedly has 18 field offices throughout Arizona, a key swing state in the 2024 election.
The shooting is another example of escalating political violence ... Kamala's opponent, Donald Trump, has been the subject of two assassination attempts, first in July and again earlier this month.