Two men have been arrested at Heathrow Airport on suspicion of terrorism offences after landing on a flight from Turkey.
The men, both aged 21, from Leicester and Birmingham, were detained by West Midlands counter-terrorism detectives just after 10am on Saturday.
They are being transported back to the West Midlands for questioning on suspicion of preparing for terrorist acts.
The arrests were intelligence-led and there was no immediate threat to the public.
It comes after three other men were arrested in England yesterday on suspicion of the commission, preparation or instigation of acts of terrorism.
Detectives from the Metropolitan Police's counter-terrorism command, assisted by officers from Sussex Police, arrested two men in Essex and a third in East Sussex at around 6pm on Friday.
The men, two aged 28 and one aged 31, are being held in custody at a south London police station.
Police have also executed search warrants at one address in East Sussex, and three addresses in east London.