The MTR says all train services, except for the Airport Express, will end again at 10 pm on Sunday to allow more time for repairs, following vandalism at its stations by anti-government protesters over the past few weeks.
The rail operator said it had made the decision following a risk assessment and after liaising with government departments.
The MTR said crowd management measures may also have to be brought in and services may be adjusted.
The Airport Express will run as normal until 1 pm. Thereafter, it will only run between Hong Kong Station and the Airport.
The protesters have been attacking MTR stations because they say the company has followed the government's line.