Increased police presence at Fairfax High School after anonymous threat posted to Twitter

An anonymous threat posted to social media has resulted in an increased police presence at a Virginia high school.

The anonymous threat was posted online Wednesday afternoon and threatened Fairfax High School, said school principal Dave Goldfarb in a note home to parents. He said that the school is working with Fairfax City Police during the investigation.

"The safety of our students and staff is our highest priority," Goldfarb said. No other information is available at this time. The investigation is still continuing.