The Long Island Rail Road said Monday that it is investigating an incident involving debris on the tracks that disrupted service Sunday night on the Port Jefferson branch.

A train hit the debris on the tracks near Syosset about 8 p.m., causing service to be suspended between Hicksville and Huntington for about 30 minutes, authorities said.

“The train struck debris on the tracks. It appears to be fencing. The incident is currently under investigation,” LIRR spokeswoman Nancy Gammerman said.

She could not explain how the debris got on the tracks.

Firefighters on Sunday night were seen using a handheld extinguisher on the debris on the tracks.

Two Huntington-bound trains from Penn Station were canceled because of the incident.

advertisement | advertise on newsday

A platform railing on the eastbound side of the tracks, a bike rack and chain link security fencing had visible, severe damage.

The railroad said the incident did not affect Monday morning’s commute.

Janet Gonzalez of Northport had spent time shopping in the city on Sunday and was headed home on the Huntington-bound LIRR train when she heard a loud noise and felt the impact of the train hitting something.

“I saw like a little bit of sparks,” said Gonzalez, 29. “It was a little bit scary.”

But she said the crash was not especially powerful — no one in her car fell down or appeared injured.

The worst part of the ordeal, she said, was what she called a lack of communication from the LIRR.

“They just told us to get a taxi, but it’s so expensive to get a taxi to Huntington, like $30,” she said, as she waited on the platform.

With William Murphy