Metro-North Railroad is warning commuters to expect delays this morning because of what are described as "mechanical difficulties in the Fairfield area.

Passengers heading west between New Haven and Stamford can anticipate delays of up to 10 to 20 minutes, according to an early-morning alert from the railroad.

Riders headed east between Stamford and New Haven will have to take buses between Fairfield and Bridgeport because of the problem.

Today's delays follow a series of heat-related problems last Friday that wreaked havoc with the afternoon commute, and continued to cause delays on Saturday.