Police investigating the murder of journalist Lyra McKee in Northern Ireland last year have arrested four men under the Terrorism Act.
The men, aged 20, 27, 29 and 52, were arrested in Derry yesterday morning and taken to Musgrave Serious Crime Suite in Belfast for questioning.
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 shot at police officers.
PSNI Chief Constable Simon Byrne, posting on social media, welcomed the arrests.
"Detectives are working hard in the pursuit of justice. Anyone with information should come forward to police," he tweeted.
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 such developments can assist in bringing those responsible before the courts and placed behind bars where they belong."
Detective Superintendent Jason Murphy renewed his call for the public to help him bring her killers to justice.
"I have always believed 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 alongside Sinn Féin's Mary Lou McDonald.
Ms McKee's funeral heard calls for political leaders to resolve their differences and restore power sharing.