The MBTA said a power problem was to blame for causing delays on the Green Line’s C and D lines on Monday afternoon.

Crews were continuing “to work to determine the exact cause,” said MBTA spokesman Joe Pesaturo, in an email.

The Green Line suffered major delays last week due to a problem on the same lines. The MBTA used shuttle buses to ferry commuters from Kenmore to Cleveland Circle on the C line and Reservoir on the D line last week, but Pesaturo said trains were continuing to travel through…