San Mateo police officers on Wednesday afternoon investigated a report of an alleged pipe bomb, but said within minutes of their initial announcement that the area was safe.
Officers tweeted just before 12:30 p.m. about police activity in the vicinity of the 2600 block of South El Camino Real.
Drivers were urged to avoid the area as roads were shut down. Once the bomb threat was investigated, roads were reopened but police warned drivers that traffic delays could be expected while they cleared the scene.
No further details were immediately available.