The Hill is reporting that the Senate Hart and Dirksen Office Buildings were evacuated due to a fire just after 1 p.m.

There are at least four fire trucks and an ambulance at the scene as hundreds of aides left the buildings. Senate staffers told The Hill that this was not a planned drill, though it is unclear why fire and rescue personnel were called.

“Evacuating hart & dirksen due to confirmed fire & audible alarm. Fire near sh-b01,” U.S. Capitol Police spokeswoman Sergeant Kimberly Schneider, said in an e-mail.

We’re working on getting some images and more details, and will be back when we know more. In the meantime, any readers on Capitol Hill care to fill us in on what you see?

UPDATE at 4:32 p.m.: The U.S. Capitol Police have given the “all clear,” and are investigating the cause of the fire, which occurred in the basement of Hart.

Several other fires, mostly in bathroom trashcans, have broken out over the last two months in Senate office buildings.