BROOKLYN - Brooklyn commuters who use the Long Island Rail Road may be in for some transit troubles through Friday morning.

Officials say the trains are running on a reduced schedule with cancellations and other changes because of an Amtrak train derailment on Sunday.

The LIRR say four westbound morning rush trains will be diverted to Atlantic Terminal Thursday. It is also advising customers to allow extra travel time and expect 10-20 minute delays.

Metropolitan Transportation Authority officials say it's still making repairs to the tracks and signals following the derailment in an East River tunnel.

Amtrak is estimating the tunnel will be back in service for Friday morning's rush. For travelers opting to take the subway instead, the MTA is honoring LIRR tickets.

The incident is still under investigation, but the NYPD says it appears a mechanical failure is to blame.

LIRR's AM service plan for Thursday, May 12LIRR statement on restoration of rush-hour service

MTA Long Island Rail Road