Several members of Maine’s largest Army Guard unit, the 133rd Engineer Battalion, were injured when a bus carrying them through a training center in Gagetown, New Brunswick, crashed Monday morning.

“A bus rolled over and 16 soldiers were sent to the hospital, treated for minor injuries and released,” Capt. Shanon Cotta of the Maine National Guard said Monday afternoon.

The Maine National Guard soldiers are training at the Canadian Forces Base-Gagetown located near the village of Gagetown. Soldiers from the 251st Engineer Company — based in the town of Norway and dubbed the sappers — are leading the training.

Sappers are engineers who specialize in gaining access to buildings, towns and other strategic locations and destroying them, Cotta said.

In Canada, “they’re conducting urban breaching operations” as part of their training, he said.

The term sapper originated from the French word “sapeur” and was first used by the French military more than 500 years ago, Staff Sgt. Robert Pearce of the Maine National Guard posted on the Guard’s website in November 2008 when the 251st was activated. “At that time, a sapper was one who dug trenches while under defensive fire to help attack an enemy fortification.”

The role of sappers has evolved over the years, and they have seen action in every American war, Pearce wrote, adding that in World War II, sappers were combat engineers who advanced with front-line infantry.

“Sappers specialize in building, laying or clearing minefields, demolitions, field defenses, general construction and building, as well as road and airfield construction and repair,” Cotta said. “The unit is also trained to serve as [infantrymen] when needed in both defensive and offensive operations and is fully involved in modern counterinsurgency operations.”

All 16 of the Maine soldiers, some of whom are members of the 251st, are doing OK after the morning rollover, Cotta said.

“It’s all minor injuries,” he said.