Prince William County police are investigating a threat that was written on a wall at Woodbridge High School.
School officials say the message threatened violence on a specific date next week.
"We take this very seriously. Whomever is responsible will face serious disciplinary action," school officials said in a post published on Facebook Thursday night.
The police department says students can expect to see an increased police presence at the school. So far, investigators say they haven't found anything that indicates this is a credible threat.
This is the second threatening message found at the school this week. According to Insidenova.com, someone scrawled "1/4/16 - 1/8/16 The school will be shot" on a wall at the school. Police say the threat was not credible.