Wellington commuters are facing delays after 12 train operators called in sick, resulting in the cancellation of 10 services on the Porirua and Taita lines.
Tranz Metro says four of the ten services cancelled on Monday evening were replaced by buses.
Tranz Metro's manager Scott Brooks says he does not know how long the delays will continue and there is no indication if the sick staff will be back at work on Tuesday.
However, he says five new drivers will be starting in the next two months, which will help to ease the staff shortage.
The following services were cancelled.
Wellington to Porirua: 3.03pm, 4.21pm and 6.03pm
Wellington to Upper Hutt: 5.07pm
Wellington to Taita: 3.50pm, 4.30pm, 4.50pm, 5.34pm, 5.50pm and 6.11pm