The Long Island Rail Road’s Babylon and Montauk branches have returned to schedule after a signal problem led to delays and cancellations Thursday morning.

Trains were previously operating with 15- to 25-minute delays while officials investigated. The railroad said they were mostly back on schedule just after 9 a.m.

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The 7:37 a.m. train from Babylon and the 7:43 a.m. train from Merrick into Penn Station were both canceled.

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The issue seemed to be weather-related, said Salvatore Arena, a spokesman for the rail service.