British police said on Friday they had arrested three men at London's Heathrow airport as they flew in from Oman on suspicion of possessing documents intended for "terrorist purposes" overseas.
West Midlands Police said the men arrested late Thursday, two of them aged 33 and one aged 39, were from the central English city of Birmingham but would not say whether they were British or foreign nationals.
"Three men from Birmingham were arrested last night on suspicion of possessing articles and documents with intent to use them for terrorist purposes overseas," the force said in a statement on Friday.
"All were detained at Heathrow Airport after arriving on a flight from Oman."
It added that the arrests by counter-terrorism officers were pre-planned and were not in response to any immediate threat to public safety.