A shot was fired on Friday at a campaign office for President Barack Obama in the western U.S. State of Colorado, shattering a window but injuring no one, police said.

Staff members were in the office when the incident occurred mid-afternoon. “It looks like it was one shot that was fired into the structure,” said Denver police spokeswoman Raquel Lopez, cited by The Denver Post .

Police were searching for a “possible vehicle of interest”, said Ms. Lopez.

Obama campaign officials did not immediately comment on the incident, which comes as Mr. Obama and Republican rival Mitt Romney battle into the final weeks before the November 6 presidential election. — AFP