The announcement comes after a journalist in Northern Ireland was shot dead in riots near the Derry-based Creggan estate in April last year, with the designated terrorist organisation reportedly admitting to the murder.
Four men connected to the murder of journalist Lyra McKee have been arrested in Londonderry, it has been revealed.
Detectives have arrested four men aged 20, 27, 29 and 52 under the Terrorism Act, the Police Service of Northern Ireland announced on Tuesday.
The PSNI and other authorities have called on witnesses to share information with authorities.
Following the arrests, senior investigating officer, Det Supt Jason Murphy said that he had “always believed that some people within the community know what happened and who was involved.
He added: “I understand that people may be frightened to talk to us. I have previously given my personal assurance relating to anonymity for the purpose of this investigation and I renew this assurance today, as we approach the anniversary of Lyra’s murder.
The senior official said he wanted Creggan residents to consider how the “horrific” attack had “impacted them personally and how it impacted the entire community”.
“We saw widescale revulsion after Lyra was murdered and I remain determined to work with the community and local policing to convert that revulsion into tangible evidence to bring those who murdered Lyra to justice,” he concluded.