The convoy of unmarked police cars and vans snaked through the streets at dawn in the Scottish town of Paisley.
By Stephen Stewart
Glasgow and west reporter, BBC Scotland news website
A police officer stands guard outside a home during one of the raids
Simultaneously, officers elsewhere in Britain were getting into position for one of the biggest operations of its kind.
The nationwide crackdown against the phenomenon of sham marriages was about to begin.
At 0600 BST, squads of immigration officials and police in Cambuslang and Paisley, in Scotland - and Reading and Thornton Heath, in England - got into position.
Just hours later, the targeted individuals had been detained and police said they had struck a major blow against a criminal operation.
The curtains of grey tenements in Paisley twitched occasionally as officials searched homes and detained suspects.
Startled residents looked on bleary-eyed, unaccustomed as they obviously were to such a hive of activity at dawn on a residential street.
Sham marriages or marriages of convenience to allow people to illegally enter and remain in the UK are big business.
Millions of pounds are generated from such schemes, which prey on the vulnerable - such as drug addicts and prostitutes - as potential spouses.
Chief Inspector Jim Boyle, of Strathclyde Police, works closely with the Immigration and Border Agency and helped organise the Scottish raids.
He said: "This has been the result of a major inquiry which began in September by the police and immigration services.
"These scams are a major source of criminal activity. This successful operation will also result in major costs savings to the exchequer."
Sham marriages have a long and less than illustrious history. Many marriages in the Middle Ages were carried out purely for political advantage or personal convenience.
One of the most famous examples was the marriage between Henry II and Eleanor of Aquitaine in the 12th Century.
Eleanor was a full 10 years older than Henry II but the marriage made France more powerful politically.
In more modern times, the practice has become a business transaction, with couples marrying in the knowledge that the marriage is solely for the purpose of obtaining legal status for the man or woman in the destination country.
After questioning, it is expected the five detained in the latest UK operation will appear before Paisley Sheriff Court on Monday.
It is hoped the court case will uncover the full extent of how Scotland has been blighted by the maverick matchmakers.