A man is to appear in court in Derry later today charged in connection with dissident activity.
A PSNI spokeswoman said the man (32) had been charged with collecting information that would be helpful to terrorists.
He and another man (31) were arrested in the Magherafelt area of Derry yesterday. The second man was released this morning.
The arrests came less than a week after British home secretary Theresa May increased the UK's threat level for a dissident republican terror attack from moderate to substantial.