The suspects are residents of Birmingham, and were arrested late Thursday as they arrived from Oman, The New York Times
The men, aged 33-39, were detained by officers of the West Midlands counter-terrorism unit, BBC News
According to The Telegraph, the men were arrested under Section 57 of the Terrorism Act 2000.
West Midlands Police have said that the operation was "pre-planned" and intelligence-led," and that the arrests made were "not in response to any immediate threat to public safety," BBC News
According to The New York Times,
a police spokeswoman said British officers had traveled to Oman to meet with authorities before making the arrests, but she did not give further details about the operation or the documents and articles the men were suspected of possessing.