The government has been urged to do more to back intellectually disabled pupils attending special schools, such as allowing them to stay there for several more years after graduation, after a wounding case in Wong Tai Sin on Thursday put the spotlight on society's support for them.

A woman, 53, was arrested on suspicion of wounding her twin sons. It is understood that the brothers, who are about 20 years old, have intellectual disabilities, and the mother has a history of mental illness.

The twins had been offered a two-year extension to stay at a special school, before returning home to live with their parents in July.

Students are supposed to graduate from special schools after completing their secondary studies and return home.

Social welfare lawmaker Tik Chi-yuen said education authorities should give more resources to special schools for pupils with intellectual disabilities so they could stay there for another two to three years.

The Third Side legislator said that would ensure better care for young people while awaiting other welfare services, such as a spot at hostels for the mentally handicapped that has an average waiting time of more than 10 years.

Tik also urged authorities to be more proactive in contacting caregivers instead of simply responding to a 24-hour support hotline, such as by working with other organisations to visit carers.

"It is quite passive because we need people to approach the service, but some people... they're distant in the community," Tik said.

Wong Wai-hung, who chairs the Joint Council of Parents of the Mentally Handicapped, noted that carers faced immense pressure when their children return home from their stint at boarding facilities.

"Throughout the years when those with intellectual disabilities have stayed at school, their families have become accustomed to how to take care of them. And suddenly, with them finishing their studies and staying at home all the time, this puts an increasing amount of pressure on their carers," Wong told an RTHK programme.

He called on authorities to provide temporary or emergency accommodation for those awaiting welfare services who are considered high-risk cases.