DISSIDENT republican Kieran McLaughlin, the chief suspect in the murder of Barry McCrory, is armed and mentally unstable, say police.
And a cross border hunt by PSNI and Garda detectives are believed to be acting on information that McLaughlin may now be in the Inishowen area of Co Donegal.
Gardaí and PSNI officers also believe that McLaughlin may try to enter the Derry City area again to carry out further attacks.
They believe he was responsible for the stabbing of a man in the Creggan area of Derry last Tuesday.
Mr McCrory was shot dead at his apartment in Shipquay Street on Thursday morning.
Anyone who sees McLaughlin should not approach him and dial ‘999’ immediately.
A search in the Burnfoot and Muff areas of Inishowen has continued this afternoon after an overnight incident where Gardaí and Irish Army personnel surrounded a house in the Brae Road area, believing McLaughlin was there.
Gardaí say the operation in the area remains ‘live’ and searches are ongoing.
Sinn Féin councillor Jack Murray called on the community in Donegal to remain extremely vigilant.