HOUSTON (Reuters) - One person was burned when a unit that makes diesel ruptured on Saturday morning in a ground-shaking blast at the Pasadena, Texas, refinery owned by Brazil’s national oil company Petrobras, the company said.

Petrobras said in a statement the fire, which started around 10:15 a.m. CT, had been contained by mid-afternoon at the 100,000 barrel per day (bpd) Pasadena Refining System refinery.

The refinery has been linked to the corruption scandal that has engulfed the Brazilian government with accusations that a significant portion of the $1.2 billion Petrobras paid for the plant, first as a joint-venture and then under its sole ownership, was returned as kickbacks to Brazilian officials, according to legal proceedings in Brazil.

“The fire has been contained and the facility is in a safe condition,” the company said. “Authorities have been notified and are supporting the response. Air monitoring has been conducted by Pasadena Refining and Harris County Pollution Control, with no indications of any off-site impacts.”

At one point it was believed three people had been injured, but a final accounting of personnel at the Petrobras refinery revealed only one person was hurt, sources familiar with emergency operations at the plant said.

Petrobras said a unit operator from the refinery was taken to an area hospital, but has since been released.

The explosion caused extensive damage to a 35,000 bpd light cycle oil hydrotreater, also called a hydrogen desulfurization unit, which uses hydrogen to convert the oil into diesel and remove sulfur, the sources said.

The hydrotreater adjoins the refinery’s 56,000 bpd gasoline-producing fluidic catalytic cracking unit.

The sources said all other units at the refinery appeared to be unaffected by the explosion and fire.

Energy industry intelligence service Genscape said the hydrotreater stopped operating after the explosion and all other units remained in operation at the refinery.

The explosion appeared to originate in the compressor of the hydrotreater, according to the sources.

A portion of the Houston Ship Channel was reopened at 12:45 p.m. CT after being shut for about three hours due to heavy black smoke from the blaze at the refinery, which is adjacent to the waterway, the U.S. Coast Guard said.

The Houston Chronicle reported that the refinery’s operating permit under the Clean Air Act and issued by the Texas Commission on Environmental Quality has lapsed. The company is applying for a permit renewal.

Petrobras spokeswoman Sophie Gates denied the company lacks the proper permits to operate the refinery.