Six people have been arrested in Dover on suspicion of Syria-related terrorism offences.
Five men and one woman were detained at 8am in the port's departure area. Police said four of the men arrested are in their 20s and from Birmingham.
In a series of tweets, West Midlands Police said: "Five men and one woman were detained at approximately 8am this morning in the departure zone of the south coast port.
"The suspects, who are not a family group and were not accompanied by children, did not pose any immediate risk to public safety.
"Searches are taking place at a number of addresses in Birmingham. The arrests are part of an on-going investigation."
Police are searching a number of addresses in Birmingham as part of an ongoing investigation.