TEMPE, Ariz. (AP) — Someone fired shots at a Democratic Party campaign office in a Phoenix suburb, causing damage but no injuries, authorities said.

Tempe police said the damage was discovered early Monday and the incident is being investigated as a property crime since nobody was in the office at the time the gunshots were fired.

Phoenix TV stations aired video Monday that showed two bullet holes in a door and two more in windows of the office.

“We are grateful to Tempe Police for coming quickly to the scene and are fortunate no one was present or injured,” Sean McEnerney, the Arizona Democratic Party coordinated campaign manager, said in a statement.

Authorities are concerned about the possibility of more political violence as the Nov. 5 general election gets closer.