Police have arrested 16 people in connection with immigration offences after officers searched homes and businesses.
The UK Border Agency operation was carried out in three towns in Angus with the assistance of Tayside Police.
Search warrants were used at residential and business premises in High Street Forfar, St Malcolms Wynd and High Street Kirriemuir and High Street Monifieth.
Three men have been detained in connection with people entering the UK illegally. Two are 30 and the third is 40.
Thirteen other people were found to be working illegally at the business addresses. They are being detained before steps are taken to remove them from the country.
Carolyne Lindsay from the UK Border Agency's Criminal and Financial Investigation team said: "The UK Border Agency will investigate and take action against those who are suspected of abusing our immigration laws for criminal gain.
"We are working with law enforcement partners throughout Scotland to take the kind of action seen in this operation."
Insp Ally Robertson of Tayside Police said that great efforts were made to keep disruption and inconvenience to customers of the establishments to a minimum and thanked them for their understanding.