Police investigating the fatal shooting of journalist Lyra McKee during rioting in Derry last month have arrested four people, including a 15-year-old boy.
Ms McKee was shot while watching the disturbances in the Creggan area of the city on 18 April.
Dissident republican group the New IRA said its members carried out the killing.
Four males, aged 15, 18, 38 and 51, were arrested in Derry this morning.
They were detained under terrorism legislation and are being questioned by detectives at Musgrave Station in Belfast.
The senior officer leading the investigation, PSNI Detective Superintendent Jason Murphy said: "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.
"They are currently in custody where they are being questioned."