They were part of five detained in a sweep of two restaurants. The men, aged 21 and 22 are detained pending removal from the UK.
The businesses that employed the workers will be find 10,000 Sterling pounds per worker, the statement said.
"If you are a business you must carry out the correct checks on your staff or you could end up with a heavy fine," the statement quoted Colin Berrington, from the Home Office Immigration Enforcement team as saying.
"We are happy to work with businesses to let them know what checks need to be made on staff, but those who break the law should know that they will face heavy fines."
UK had toughened civil penalties against businesses employing migrants who had not come through official channels, last week.