Anti-terror police have arrested a boy and a girl, both aged 16, in raids in Mossley, Greater Manchester.
Police said searches were continuing at addresses in Hanover Street and Spring Mill Drive, Mossley.
The teenagers were arrested on Monday on suspicion of being concerned in the commission, preparation or instigation of an act of terrorism.
They are being held in police custody.
Chief Superintendent Caroline Ball said: “I know news of an arrest made under terrorism legislation in this community will cause a certain amount of anxiety and people will understandably have questions.
“What I want to stress very clearly is that this investigation is in no way linked to any sort of international terrorist plot nor have we recovered any evidence to suggest the community of Mossley is at risk.
“This investigation has arisen as a result of information from law enforcement agencies so it is prudent we act on that information and carry out a thorough, professional investigation to determine the circumstances and details of the activity reported.”
She said the searches would last several days but said people should interpret the ongoing police activity as reason to be reassured rather than concerned.
Chief Supt Ball added: “Again I would stress there is no current threat to either the Mossley community or wider and there is no reason to be unduly worried.
“If anyone is concerned, please approach one of local officers who will be happy to speak to you.”
Anyone with concerns about suspicious activity can contact police or the confidential Anti-Terrorist Hotline on 0800 789321.
:: Meanwhile, a Stoke-on-Trent man has been arrested on suspicion of encouraging terrorism and supporting a proscribed organisation. The 29-year-old’s arrest relates to suspected online postings which reference the Islamic State.