Detectives investigating the murder of Lyra McKee have arrested four people.
The four males are aged 15, 18, 38 and 51 and were arrested under terrorism legislation.
The 29-year-old journalist was shot while present at disturbances in Londonderry last month.
Dissident republican group the New IRA said its members carried out the killing.
The suspects have been taken to the serious crime suite in Musgrave Station, Belfast where they are being questioned by detectives.
Detective Superintendent Jason Murphy said the arrests came after searches at four houses.
“As part of this morning’s operation detectives carried out searches at four houses in the city and arrested four people in connection with the violence which was orchestrated on the streets of Creggan on the evening of Lyra McKee’s murder,” he said.
“They are currently in custody where they are being questioned.
“I want to thank the public for the widespread support we have received to date, including more than 140 people who have provided images, footage and other details via our dedicated major incident public portal.
“I still want to hear from anyone who can tell us anything they know.