Six people have been arrested in Dover on suspicion of Syria-related terrorism offences, the BBC quoted West Midlands Police as saying on Friday.
Five men and one woman in their 20s were detained at about 08:00 BST on Friday in the departure zone of the Kent port, police said on Twitter.
Searches are taking place at a number of addresses in Birmingham.
Police said the arrests were part of an on-going investigation, and the suspects are not a family group and were not accompanied by children.
Four of the men arrested are from Birmingham and in their 20s, police said.
A man aged 26 and a 23-year-old woman of no fixed address were also held.
The suspects are being questioned at a police station in the West Midlands area.
They did not pose any immediate risk to public safety, the force added.
Source: MENA