Four people have been arrested by detectives investigating the murder of journalist Lyra McKee in Co Derry.
Detectives from the PSNI's Major Investigation Team made the arrests under terrorism legislation.
Ms McKee was shot dead while covering rioting on April 18th.
The four men - aged 15, 18, 38 and 51 - were arrested in Derry city on Thursday morning in connection with the violence.
Police carried out searches at four houses in the city.
The four have been taken to a Serious Crime Suite in Musgrave station, Belfast where they are currently being questioned by detectives.
The senior detective leading the investigation is Detective Superintendent Jason Murphy.
He 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.
"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."