Firefighters have contained the fires which broke out along the train line between Aylesbury and Darfield this afternoon.

17 Fire and Emergency crews, as well as the three helicopters are still dealing with multiple hotspots along the train line.

Preparations are underway to re-open State Highway 73.

A KiwiRail spokesperson told Chris Lynch Media a freight train shunting wagons from a milk factory in West Rolleston was held back near Darfield earlier today after it created a number of grass fires along the track.

The train was stopped while the incident was being investigated. No one was hurt.

The track is now closed overnight between Rolleston and Darfield.

Affected services overnight include the TranzAlpine travelling from Greymouth to Christchurch with 172 passengers on board. Overnight freight services are also affected.

Bus replacements are in place for the TranzAlpine passengers.

“We are sorry for the inconvenience, but safety has to be our top priority” the spokesperson said.

Meanwhile, there are no longer any homes under immediate threat from fire and there have been no reports of any homes sustaining damage.