Armed officers joined those from the counter terrorism command when the arrests were made at about 4am.
Police say the operation was not linked to the Olympics.
A 38-year-old woman was also arrested for alleged fraud offences and two other men were held over alleged immigration offences.
More top news
The Duke of Cambridge is to end his role as an air ambulance pilot and become a full-time Royal, Kensington Palace has announced.
The UN released the before and after images and described the damage, reportedly caused by Islamic State, as 'a new war crime'.
The 16-year-old's body was found on January 16 on a pathway in Dinnington, South Yorkshire.