A smoky three-alarm fire closed a major bridge over the East River on Tuesday afternoon, and five firefighters suffered minor injuries battling the blaze.

Part of the bridge reopened late Tuesday and the remainder was expected to open Wednesday, the Department of Transportation (search) said.

The fire on the Queensboro Bridge (search), which apparently started in scaffolding and a canvas tarp, produced heavy smoke that could be seen for miles.

Construction workers were painting steel on the upper deck when the fire erupted, Deputy Fire Chief Robert Sweeney (search) said. The tarp, used during sandblasting, suffered the greatest damage, he said.

More than 100 firefighters were sent to the steel bridge, which spans the river between 59th Street in Manhattan and Long Island City in Queens.

"We needed a tremendous amount of manpower to get the water and the hose up to extinguish the fire," Sweeney said.