Marines have joined the earch for missing Arbroath serviceman Ralph Hebden.
Vehicles filled with troops from 45 Commando assisted police in the hunt for their colleague on the East Seaton estate yesterday evening.
Six people carrier cars were seen parked on a farm track as teams of up to 30 marines from RM Condor combed the area.
One member of a search party returning to the vehicles around 5pm confirmed they had had no success in locating Mr Hebden or picking up any leads.
Tayside Police released CCTV images of Mr Hebden (32), who was last seen by friends and family on Monday morning.
His image was captured on the closed circuit cameras at Morrisons, in the town’s Hume Street, at about 8.30am.
Police also interviewed shoppers outside Morrisons looking for fresh information as the hunt entered its fourth day.
There was also a police presence at the town’s bus station after officers confirmed they were investigating a number of sightings of the serving marine throughout the UK.
Police are not discounting that Ralph, originally from Liverpool, may have travelled to the Merseyside area where he has friends and family.
Meanwhile searches in Arbroath resumed, with a focus on sheds, garages and outbuildings to establish whether he had sought temporary refuge at any point during the time he has been unaccounted for.
Inspector Ally Robertson said: “We would ask householders to follow our lead and check their outbuildings for any sign that someone might have been there.
“If they spot anything suspicious, they should call us right away. As time goes by our concerns for Ralph increase as, more significantly, does the concerns of his loved ones.”
His pregnant wife Sarah has made her own appeal for her husband to get in touch.
Ralph was known to go on very long walks, heading miles outside of the Arbroath area, sometimes venturing as far as Barry Buddon and even the Carse of Gowrie.