A fourth man, 26, was arrested at Gatwick Airport in the early hours of Friday. All five are from Birmingham.
Whitehall officials described the arrests as "significant".
Police say they worked with MI5 and Belgian and French authorities in an operation "to address any associated threat to the UK following the attacks in Europe".
`Extensive investigation`
They said there was no risk to the public at any time and they had no information to suggest an attack in the UK was being planned.
It is understood that the man arrested at Gatwick Airport had just arrived on a flight into the UK originating in North Africa.
Police said all those arrested are being held in the West Midlands on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.
Officers are also searching a number of properties in Birmingham.
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