Citybus on Saturday thanked passengers for their understanding after one of its buses left the usual route and diverted to a hospital because a child on board was sick.

The 79X bus was supposed to go from Cheung Sha Wan to Fanling's Queen Hill.

But as it was travelling along Tolo Highway at around 10pm on Friday, the driver decided to first go to Nethersole Hospital in Tai Po.

The driver deemed the situation to be an emergency, Citybus said.

After going to the hospital, the bus went back to its original route, the company said, adding that it was looking into the matter.