GILLETTE, Wyo. (AP) — BNSF Railway officials are investigating a seven-car derailment in northeast Wyoming. No one was injured in the incident.

The derailment occurred about 3:40 p.m. Friday as the train was performing a switching move in Gillette.

BNSF spokesman Ross Lane says the derailment happened as a train was picking up additional cars.

Some of the cars were carrying freight but nothing spilled.

The derailment blocked both main tracks, but both tracks were reopened by about 6 a.m. Saturday.

The delay affected six trains on that route, but the overall impact was not severe, he said.