CN (TSX:CN) said the derailment happened around 2:20 p.m. Friday in a rural area near Grand Falls, N.B., when six cars went off the tracks as the mixed-cargo train was entering a side track off the main line at about 10 kilometres per hour.
Spokesman Jim Feeney said all of the cars remained upright, none of the cars were carrying dangerous goods and no one was injured.
"This is a very minor incident," said Feeney in a phone interview on Saturday afternoon. "There were no dangerous goods, there are no leaks, no spills, no injuries and the main line has been reopened."
Feeney said two cars were carrying automobiles, two were loaded with fertilizer, one was carrying wooden rail beams and another was empty.
He said the cause of the derailment is under investigation.
The Transportation Safety Board of Canada said it is not sending an investigator to the site and the incident has been deemed a class five occurrence, which means it is recorded in the board's system for possible future safety analysis, statistical reporting or archival purposes.
Spokeswoman Julie Leroux would not elaborate on why the derailment was deemed a class five occurrence.
It's the third CN train derailment in northwestern New Brunswick this year, including one about an hour from Grand Falls in Plaster Rock on Jan. 7, where 19 cars left the tracks and sparked a major fire that burned for several days.
Later that month, five freight cars including one carrying liquid butane left the tracks in the Edmundston community of Sainte-Basile, although there was no leak or fire in that derailment.