Three men are being held under the Terrorism Act following a raid at a house in Wales.
Two 24-year-olds and a 41-year-old were initially arrested on suspicion of drug offenses by Gwent Police at a house in Blackwood, South Wales, on Wednesday.
Following further inquiries, the Metropolitan Police Service Counter Terrorism Command was called in the following day.
They further arrested the trio on suspicion of the commission, preparation or instigation of acts of terrorism under the Terrorism Act 2000.
The men have since been transferred from South Wales to a police station in the central London area.
A spokeswoman for Gwent Police said the inquiry was not linked to international terrorism.
"I have got no idea how long the men lived there. They were supposed to be builders and it was supposed to be chemicals that were found there," said a neighbor.