Armed police staking out a former nuclear bunker in Fife said they are now talking to a man hiding inside.
Firearms officers and negotiators were called to the bunker
Firearms officers and negotiators were called to Scotland's Secret Bunker near Anstruther, which is now a Cold War museum, at about 0130 BST on Tuesday.
The man is understood to be Ronald MacDonald, a 39-year-old who had been living rough in the area.
Mr MacDonald's plans are unclear, but police said they hoped the situation could be resolved soon.
Scotland's Secret Bunker is hidden 100ft underground below a farmhouse at Troywood.
The tourist attraction contains knives and imitation firearms, while its canteen is stocked with food.
The complicated layout of the building, which provides 24,000 sq ft of accommodation on two levels, provides plenty of hiding places.
Police revealed the man arrived at the museum in a mechanical digger, which is still at the scene.
Chief Supt Maich refused to specify a time frame in which he hoped to have the
situation under control.
He said: "We want a safe solution to this situation.
"We are not working to any timescale.
"If it means waiting long term then we are willing to do that and we have
resources in place to accommodate that."
Police teams are treating the situation extremely seriously because of the
possibility that the man could harm himself or other officers, Chief Supt Maich
He said: "The way we have got to look at it is that he has access to these
"There is obviously a risk to himself and to officers and we have got to
treat the situation very seriously.
"There are no weapons in there that he has access to which
aren't decommissioned. That is all I'm prepared to say on that one."
Speaking at the scene on Wednesday, the general manager of the bunker, Jim
Braid, said he understood that a "status quo situation" remained.
There are replica weapons on display inside the bunker
He said: "I can understand why the police have taken the softly-softly approach,
because they just don't know if the guy is armed or not."
Mr Braid said the man would have access to food and drink from the museum café and would be able to sleep in comfort in one of the dormitory bunk beds.
He said his real concern was that the intruder would damage irreplaceable items in the collection.
The nuclear bunker was built in 1952 and lay hidden 100ft underground beneath
A tunnel leads to the bunker, which has 24,000sq ft of secret accommodation.
Formerly an RAF radar station, it was taken over in the 1960s by the Civil
Defence Corps to be the seat of Scottish government in the event of a nuclear
The bunker has 15ft-thick walls of reinforced concrete with space for 300
people to live, work and sleep in safety.