Live Updates: Police investigating active shooter situation at Texas high school

Texas police are investigating an active shooter situation at Timberview High School in Arlington, Texas, the school district confirmed to CBS News. The school is on lockdown and the investigation is ongoing. 

CBS Dallas-Fort Worth reported that the first call for service came at about 9:30 a.m. local time. There is a heavy police presence at the school. 

Arlington police confirmed they are on the scene, conducting a "methodical search" of the area.