Five people have been jailed and another 20 arrested as part of a Hong Kong Immigration Department crackdown on illegal employment this week.

The department said on Friday that it had raided 23 locations, including restaurants, cleaning companies and commercial buildings, as part of an operation that ran from Monday to Thursday.

Those arrested comprised 19 people found or suspected to be working illegally and six employers who allegedly hired them. The larger group consisted of six men and 13 women, aged 22 to 62.

Thirteen of those arrested held tourist visas, comprising 11 from mainland China and two from Indonesia.

A former domestic helper who allegedly overstayed, an illegal immigrant and four holders of recognisance forms, which prohibit them from working, were also arrested in the operation.

Ng Kwun-cheong, the deputy commander of an Immigration Department task force tackling illegal employment, said five people among those apprehended over illegal employment had already received prison sentences ranging from 51 days to 14 months.

“Most of the arrested illegal workers took up the jobs, including dishwashers, cleaners and working in kitchens as general workers,” he said.