Five men have been arrested on suspicion of terrorism offences in east London and Dover, after police stopped a vehicle leaving the UK from the port.
Officers from the Metropolitan Police Counter Terrorism Command said two men aged 33 and 43 were held after officers, with the support of Kent police and the MPS Specialist Firearms Command, stopped a vehicle going outbound at Dover port.
The pair were arrested on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.
Scotland Yard said a 37-year-old man was arrested on suspicion of people trafficking offences and a further 12 men and one woman who were stopped in the same vehicle were also arrested on suspicion of immigration offences by Immigration Enforcement officers.
Three more men, aged 24, 28 and 40, were arrested the following morning in east London and in Dover on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.
Five addresses in east London and south London are also being searched as part of the investigation.
A Met Police spokesperson said the operation is not in response to any immediate threat.