Northbound Interstate 805 closed shortly after 8:30 a.m. on Friday for police activity, according to officials.
The interstate is closed at the state Route 54 connector between Chula Vista and National City. A SigAlert has been issued warning drivers to avoid the area.
Click here for the NBC 7 San Diego traffic map
Traffic is being diverted to SR-54 while the Plaza and Sweetwater onramps are closed.
Check back for updates on this story.