Federal investigators say CN railcars that spilled crude after derailing on farm land in western Manitoba were upgraded tankers.

The Transportation Safety Board says 37 of 110 cars went off the tracks early Saturday near St. Lazare.

The board says the derailed tankers are all Class 117R cars — an upgraded version considered to have improved safety features over the cars that were involved in the 2013 fatal explosion and fire in Lac Megantic, Que.

There was no fire or injuries in the weekend derailment and the board says most of the crude has been contained near the tracks.

The board says it is still working to determine how much oil spilled and how many of the railcars were breached.

Investigators will also review how well the upgraded tanker cars performed in the derailment.

The TSB says the Canadian National train was rolling east at around 79 km/h when it experienced a train-initiated emergency brake application.

Barry Lowes, reeve of the rural municipality of Ellice-Archie, said the spilled oil was in a small area on top of deep ice and snow on a pond. Crews have built a berm around the area to contain the

spill.

About 37 crude oil cars have derailed near a village in western Manitoba. Crews were working to clean up the scene into Saturday afternoon. (Riley Laychuk/CBC)

Some cars that have been pulled from the pileup are full of crude and others are empty, Lowes said.

Crews were pumping oil out of the intact rail cars, he added, and vacuum trucks were sucking up the crude from the landscape.

"They have no idea how much oil has been leaked out," he said Tuesday. "They figure the cars will all be moved and emptied by the weekend."

Lowes said he has been told the cleanup will also include scooping soil up from the spill area and ongoing monitoring.

"They are doing everything that you would want them to," he said. "There are environmental people all over. They are not cutting any corners."

The Manitoba government has said there is no danger of the oil entering the nearby Assiniboine River.

Jayme Corr, who has 250 cattle on almost 1,000 hectares of land, has said he is depending on the cleanup. He uses the pond to water his cattle in the summer.