A Union Pacific freight train derailed in downtown Longview Thursday around 4 p.m., blocking downtown streets.

No injuries were reported in connection with the derailment. About 20 railcars were derailed but remained upright, said Mike Jaixen, senior manager of communications for the railroad.

No materials were released from any of the cars, Jaixen said.

Fredonia, Center and Horaney streets were blocked as of 5 p.m. The 500 block of E. Cotton Street was also blocked. Drivers and pedestrians are urged to avoid the area.

The derailment occurred near the intersection of First and Tyler streets. Railroad personnel are on scene and working to clear the area, police said.

This story will be updated with more information as it becomes available.