Police officers investigating the murder of a construction worker at a Territorial army base in Derry last week have again appealed to the public for information.
Mr David Caldwell (51) died after he picked up a device, hidden in a lunchbox, at Caw Camp on the Limavady Road last week. Dissident republicans have been blamed for the killing.
Insp Stephen Cargin said it was a "brutal and savage attack" on Mr Caldwell and the local community.
"We would ask anybody to come forward with any information they can to help us to put these people behind bars where they deserve to be," he said.
A man who was detained in Sion Mills, Co Tyrone, on yesterday morning is being questioned about the murder.
