SAINT JOHN, New Brunswick — A massive explosion at an Irving Oil refinery Monday morning shook the eastern Canadian city of Saint John, but caused no fatalities.

Irving Oil said several contractors are being treated for non-life threatening injuries.

Litsa Daeres, 34, who lives nearby, said she just started preparing Canadian Thanksgiving dinner when she heard a loud bang.

"My whole house shook," she said. "I thought my furnace had exploded."

Daeres said she opened her curtains and saw flames and thick, black smoke.

Flames were still visible later in afternoon, and there were four separate sources of water being poured on the blaze.

The refinery is near several residential neighborhoods on Saint John's east side.

New Brunswick Emergency Measures Organization spokesman Geoffrey Downey said no evacuation orders had been issued, but there was an "order to shelter in place for anyone living in the direction of the plume."

Nate Guimond, 36, said he was doing house repairs when he saw smoke.

"I heard a rumbling, roaring sound," Guimond said.

He decided to drive by the refinery and said he was nearby when he felt the vibrations of what he assumes must have been a second explosion.