Armed police told guests at a birthday party not to leave their hotel during an incident at a nearby house in Dumfries.
The 60 guests were at a function to celebrate a 50th birthday party at the Mabie House Hotel.
Police officers ordered them to stay in the building during the incident which lasted for an hour.
It happened at a house at Mabie, on the outskirts of the town at around 10:12pm on Saturday.
A 63-year-old was detained and enquiries are ongoing.
The party was being thrown for the 50th birthday of Lynne Longmore, from Lochmaben.
She said that some of her guests thought the armed officers were in fancy dress as part of the celebrations.
But once the seriousness of the situation was known, everyone stayed calm till the incident was over.
We had just had the fireworks. Everybody was just coming in for birthday cake when the police arrived in a van and all we could make out was that they were armed. I initially thought someone had complained about the fireworks.
Then quite quickly 3 more police vans arrived. We were told to stay inside and mustn't leave the hotel until it was clear.
It was quite a serious incident but everybody stayed calm and were philosophical about it all.
It's a birthday I'll always remember that's for sure.