A portion of Southern Boulevard in Nesconset, closed Tuesday morning due to an electrical issue in the area, was reopened about 9:45 a.m., Suffolk County police said.

But, police cautioned that roads in the area may need to be shut down again “periodically,” so that crews from PSEG Long Island can conduct emergency repairs.

Southern Boulevard had been closed between Smithtown Boulevard and Gaynor Avenue about 7:45 a.m., police said.

The nature of the issue was not immediately clear, but Suffolk fire officials said it involved “electrical issues” to a number of buildings and later involved at least one reported “basement fire,” according to the Nesconset Fire Department.

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A PSEG spokeswoman said an emergency crew responded to the scene and, at the request of fire officials, de-energized service in the area, which initially affected about 975 customers.

Spokeswoman Elizabeth Flagler said service had been restored to all but about 200 customers by 10 a.m. and that PSEG hoped to have 95 percent of the customers back online by 11 a.m.

The first 911 call reporting electrical issues in the area was received at 6:47 a.m., fire officials said. Another call was received at 7:32 a.m. Police said the later call reported wires down in the area and initial reports were that the downed wires were electrical. However, Flagler said the downed wires were “cable wires, not electrical” — though it still was unclear what caused any wires to be downed. Police said there were no reported accidents in the area and fire officials could provide no immediate cause.

Police said it was likely arson detectives would investigate, but could not immediately confirm they were on scene.