Immigration officers today arrested 22 people in a crackdown on illegal workers.

From 7am to 4pm, the officers raided 17 businesses and checked the identity of over 100 people.

Eighteen Mainland visitors - 14 men and four women aged 24 to 58 - were arrested for breach of conditions of stay.

Four Hong Kong employers - two men and two women aged between 42 and 51 - were also arrested for employing illegal workers. They have all been detained for further inquiries.

The Immigration Department warned that visitors were not allowed to take up employment, whether paid or unpaid, without prior permission from the Director of Immigration.

Offenders are liable to prosecution and, upon conviction, to a maximum fine of $50,000 and two years' jail.

It is also an offence to employ people who are not lawfully employable. The maximum penalty is a fine of $350,000 and three years' jail.