It's believed a lightning strike touched off a major fire at a Saskatchewan oil storage depot, the RCMP says.

The fire started early Friday morning about 15 kilometres southwest of Stoughton.

Fire fighters from the Stoughton Fire Department were called to the scene at around 3 a.m. CST.

When they arrived, seven out of 12 large storage tanks were ablaze.

The depot is owned by Crescent Point Resources. Crews extinguished the fire, the RCMP said.

No one was hurt.

The RCMP investigated and didn't find any evidence that it was deliberately set.

A severe storm system had been moving through the area on Friday and it's now believed a lightning strike was responsible, the RCMP said Monday.