A Newark firefighter who suffered serious injuries Saturday battling a blaze at a tire shop has been upgraded from critical to stable condition, officials said.

Paul Leber, 38, gave a thumbs up Monday to Mayor Ras Baraka, Public Safety Director Anthony F. Ambrose and Fire Chief Rufus Jackson when they visited him at Jacobi Medical Center in the Bronx, Ambrose said.

Newark firefighter Paul Leber, left, is shown with Bill Bishop, a city employee and fellow veteran, during a 2010 Memorial Day event. (File photo courtesy of the City of Newark)

Leber responded with other members of Engine 7 -- including a probationary firefighter -- at 9:12 p.m. to a two-alarm fire at Velez Tire and Auto on Park Avenue.

When conditions worsened and they were ordered out of the building, Leber became disoriented. Other members of Engine 7, Rescue 1, went back into the building to rescue him.

The fire remains under investigation by the Newark Arson Unit, Ambrose said.

Leber suffered burns to his face and airway from heat and smoke inhalation, Ambrose said Monday.

"He has improved," Ambrose said. "He is sedated. He has a long road to recovery. We need to keep praying."

Leber, a graduate of the Bergen County Fire Academy who was born in Passaic, joined the department after serving in the U.S. Navy aboard the USS Theodore Roosevelt, a Nimitz-class aircraft carrier.

Allison Pries may be reached at apries@njadvancemedia.com. Follow her on Twitter @AllisonPries. Find NJ.com on Facebook.