A swath of a Texas town was advised to evacuate on Thursday after authorities said they were responding to "an ongoing bomb threat" near a county courthouse.The evacuation zone spans a 2-mile radius in the downtown Angleton area near the Brazoria County Courthouse, the Brazoria County Sheriff’s Office wrote in a post on Facebook."A threat has been made near the Brazoria County Courthouse, and as a precaution, the courthouse is being evacuated," the sheriff's office wrote in an earlier post. "At this time, we ask everyone to avoid the area within a two-mile radius of the Brazoria County Courthouse, as BCSO Deputies work to investigate further."Authorities have established a perimeter and shut down several roads in the area.HOUSTON POLICE UNION SLAMS ‘ROGUE’ JUDGE FOR LETTING MAN ACCUSED OF KILLING DEPUTY OUT ON BOND: ‘DISGRACEFUL’It’s unclear how or who made the threat. It also remained unclear whether authorities found the reported bomb.This is a breaking news story; check back for updates.