Gardaí are searching a forest in Co Louth as part of a PSNI murder investigation into the disappearance of a woman more than two years ago.
It is believed that Saoirse Smyth (28), who went missing in Belfast on April 11, 2017 may have returned to the house where she had been living at Essmor Cottages in Omeath.
Yesterday's search operation focused on a wooded area near that village.
"This is an operational search rather than an intelligence-led search," a senior source told the Irish Independent.
Gardaí announced details of the operation, which follows the forensic examination of a house last July in Omeath by officers searching for DNA or fingerprint evidence.
That search lasted for two days but no trace of a body has yet been found.
"The search is being conducted by detectives from the National Bureau of Criminal Investigation (NBCI), supported by the Louth Divisional Search Team, Garda Technical Bureau, specialist forensic archaeologists and specialist cadaver search dogs," a Garda spokesman said.
"Investigators from the Police Service of Northern Ireland will also be assisting."
It is feared that Ms Smyth, who had distinctive red hair and was around 5ft tall and of slim build, may have been murdered.
Last July, the PSNI arrested a 40-year-old man on suspicion of Ms Smyth's murder in the Newry area but he was released without charge.
A 48-year-old woman was also arrested and released by the PSNI.
It has also been reported that the PSNI would like to question a Northern Irish drug dealer who is currently serving a jail sentence in Mountjoy Prison.
In an appeal last year, Ms Smyth's family urged anyone with information to come forward. "Somebody out there must know something about what has happened to Saoirse and we would plead with anyone who knows anything to contact the police," the family said.
PSNI Detective Chief Inspector Geoff Boyce said the investigation into Ms Smyth's disappearance had "progressed" but that "while keeping an open mind, I now believe that the potential exists for Saoirse to have sadly been murdered".
Urging anyone with information to come forward, Det Boyce said: "Her family deserve to know what has happened to her.
"I have been in contact with her family, who understandably have been left devastated, and trained police family liaison officers are supporting the family at this very difficult time."
Gardaí are asking anyone who has information to contact Dundalk garda station on 042 9388470 or the Garda Confidential Line 1800 666 111. The PSNI can be contacted on (0044) 28 9070 0355.