KEY POINTS:
The North Island main trunk rail line is blocked this morning after a derailment in Hamilton.
One wagon from a freight train came off the tracks near Kilarney St, Frankton, at about 5.30am, Toll NZ spokeswoman Lisa Gibbison said.
The driver was not injured.
Five wagons were still blocking the line and rail workers were at the site working on clearing the track.
Ms Gibbison said the company had no idea what had caused the derailment, but would be investigating.
Two freight trains had been disrupted by the track closure, she said.
- NZPA
