Three men arrested by police investigating the murder of journalist Lyra McKee have been released.
A 29-year-old man was released without charge.
Two others, aged 20 and 27, who were also arrested in Londonderry on Monday, were released pending a report to the Public Prosecution Service.
A 50-year-old man remains in police custody.
Police said their investigation is ongoing after Ms McKee was shot dead in the Creggan area of the city on April 18 as she observed rioting.
The New IRA admitted responsibility for the murder, saying she had been shot accidentally by one of its members while they fired at police officers.
DUP Foyle MLA Gary Middleton said the arrests were a "positive development" in the police investigation.
"The vicious and indiscriminate murder of Lyra McKee by the so-called New IRA was unacceptable and rightly rejected across the board," he said.
"It is our hope that such developments can assist in bringing those responsible before the courts and placed behind bars where they belong.
"The PSNI has made it clear that the local community still holds the key to answers in relation to this awful crime, particularly in relation to mobile phone footage and first hand witnesses.
"We would urge anyone with any information to come forward to the PSNI as soon as possible."
Detective Superintendent Jason Murphy renewed his call for the public to help him bring Lyra's killers to justice.
"I have always believed that some people within the community know what happened and who was involved.
"I understand that people may be frightened to talk to us," he said. "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."
There was widespread condemnation in the wake of the murder which saw DUP leader Arlene Foster join a vigil at the scene of the killing alongside Sinn Fein's Mary Lou McDonald.
Ms McKee's funeral heard calls for political leaders to resolve their differences and restore power sharing.
Mr Murphy added: "I want the community in Creggan to think about how that horrific attack 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 said.
"I also know that many people were recording mobile phone video clips that night and while we had a huge response to my initial appeal for those videos, I believe that others may exist.
"I would ask anyone who has mobile phone footage to upload it onto our Major Incident Public Portal at www.MIPP.police.uk."