The MTR Corporation on Wednesday said it would close a major stretch of the Kwun Tong Line for a rare, full-day maintenance operation later this year.

There will be no service between Prince Edward and Ho Man Tin on Sunday, July 28.

Cheris Lee, who heads the corporation's operating and metro segment, said all four stations affected would still be served by either the Tsuen Wan or Tuen Ma lines, while free bus services would run between Yau Ma Tei, Ho Man Tin and Whampoa.

She said the asset renewal work would be completed in time for people to get to work on the following Monday.

"I think the reason why we chose the 28th of July is because it is in the middle of the summer holiday. We believe that quite a number of citizens will be on holiday on that day, and that students also have no school on that day. We are trying to minimise the impact to the passengers and also to the citizens in the town," she said.

KH Lee, chief of the corporation's operations engineering maintenance, said they would replace more than 50 large metal hangers used for hanging power cables on the tunnel ceiling of the crossover near Yau Ma Tei Station, adding the work was necessary based on asset condition and life cycle.

"There are lots of complexity not only because of the preparation of those safety precautions, but also all the work associated with this sort of hangar replacement, like in the course of the hangar replacement, we have to relocate and dismantle some of the existing overhead line and also their parts," he said.

"Upon completion of the work, we have also arranged tests to ensure every system is in good order before we resume the service, so there's a reason why we have decided to have a one-day closure together with the two non-traffic hours.That means before and after to complete the work in one go."

He added several stations would need to carry out similar tunnel facility renewal projects in the next three years.

Some people RTHK spoke to said repair work was inevitable for maintaining efficient railway services.

"There needs to be maintenance from time to time as facilities start to age, or there will be more signal failures in the future. That would lead to longer waiting times, which is very troublesome for people," said a man surnamed Wong.

Another man named Tsoi said he would leave earlier than his usual time when using the train that day.

A woman named Lam said she is a bit worried that there will be huge crowds while travelling that day.

"It could be quite disruptive to people especially since they are working during travelling hours at some of the busiest stations," she said.