The parents said they only had 14 days from the time of the letter to decide where to enrol their children.

Angel Ngo On-kei, a spokeswoman for the parents’ group, said it would be tough on parents and their children to attend a school that was far away.

“Our children tend to have issues with their emotions and physical conditions, which need the help of parents,” she said. “If our children are studying in Tseung Kwan O, it will be difficult for us to reach the school immediately and could cost more than HK$200 [US$$25]to take a taxi there.”

Ngo said her son, who is 5 years old and has moderate intellectual disability and autism, sometimes had episodes of crying and shouting for hours.

For his current kindergarten, she could take him home to rest and then back to school, which is within walking distance. It would be difficult to help him, she said, if the school was not near their home in Tsuen Wan.

Ngo and four other parents eventually enrolled their children in a school in Sha Tin, which is relatively closer in eastern New Territories. She pointed out that the bureau did not tell them about the Sha Tin option, which they found on their own.

Some parents had no choice or were not aware of this option, Ngo said. She estimated that eight children would be going to the Sham Shui Po school and seven to Tseung Kwan O.

Ngo said she understood that parents of three pupils did not pick any of the other schools, meaning they could be betting on leftover places in nearby schools or having their child repeat the final year of kindergarten.

She pointed out that if pupils missed the school bus, it could take as long as two hours to go to Tseung Kwan O using public transport.

Ngo said the bureau told parents that a school meant to open in Tung Chung in the coming academic year had to postpone its opening. That was why pupils from the district currently attending the Tsuen Wan and Kwai Tsing schools could not return to their home district and free up places.

Ngo criticised the government for not building any new schools for those with moderate mental disabilities in Tsuen Wan and Kwai Tsing since the 1980s. She said schools had met rising demand by increasing the number of places in the two current schools.

The parents called on authorities to make sure the affected pupils could return to their home district to study in the 2020/21 school year. They also asked the city to facilitate school bus arrangements so the daily journeys would not be too long.

An Education Bureau spokeswoman said there were more pupils with moderate intellectual disability entering Primary One in Kwai Tsing and Tsuen Wan than usual. She said the two schools there did not have enough space to accommodate new classes, and that was why these pupils had to go to schools in other districts.

Based on current statistics, she said these pupils could return to their district from September 2020 when a new special school opens in Tung Chung.

The spokeswoman said the schools in other districts that took in the pupils had some preliminary school bus routes that would take about as long as if the children studied in their home districts.

She said the bureau would help these schools to lower school bus fares as much as possible.

The number of pupils with moderate intellectual disability studying in special schools went up from 1,865 in the 2014/15 school year to 2,040 in 2018/19.