Fire officials ruled Monday that an arsonist set a huge blaze that engulfed tons of recyclable paper products and wooden pallets outside a business west of downtown Minneapolis and nearly ignited a tank of fuel close by.

The blaze broke out shortly after 11 p.m. Saturday at the Pioneer Industries at 179 N. Irving Av. and sent large clouds of smoke skyward with the downtown skyline as a backdrop.

There were no employees on the property at the time, and no arrests have been announced as of Monday afternoon.

It took about two hours to bring the blaze under control and another five-plus hours before fire crews had the last of the flames doused and felt it was safe to leave the scene about 6:30 a.m. Sunday.

Along with the several 2,000-pound bales of paper products and the pallets, flames also consumed a large pile of plastic containers filled with highly flammable plastic scrap, the Fire Department report disclosed.

The flames narrowly missed a large tank with diesel fuel, the report noted.

“The amount of fire encountered combined with the fire load present could have easily spread to adjacent structures and led to a much worse outcome had it not been for the quick action and decisionmaking from the responding crews,” said Assistant Fire Chief Bryan Tyner.

The official determination of arson confirms what site general manager Mark Elsbernd told the Star Tribune. Elsbernd said company video surveillance images showed one of two suspects setting a compressed bale of paper on fire, which then spread to many other bales.

Pioneer has been operating in Minneapolis since 1894 and at the Irving Avenue site since the mid-1960s, he said. The Star Tribune is among Pioneer’s many clients.

The company is based in suburban Chicago and operates in five other central U.S. states.