A third rail problem in one of the East River tunnels prompted a westbound service suspension between Jamaica and Penn stations and Woodside and Penn stations for much of the evening commute, the LIRR said.
Service was restored shortly after 6 p.m., LIRR officials tweeted.
The service suspension came as the railroad urged commuters to expect cancellations and delays as service remained suspended in both directions between Port Jefferson and Huntington while repairs were made to a broken rail, the LIRR said.
Before the evening commute, the Long Island Rail Road advised riders on the Port Jefferson line to use the Ronkonkoma branch. Limited bus service was being provided in the meantime, while crews repaired the broken rail east of Huntington, the railroad said.
Service was temporarily suspended during the morning commute in both directions, between Huntington and Port Jefferson, because of the rail issue, the LIRR said.
The LIRR sent alerts via social media starting just after 5 a.m. Service was restored shortly before 7 a.m.
Crews were on the scene later, shortly before 10 a.m., making permanent repairs, the LIRR said.
More information is at the LIRR website, mta.info/lirr.