12:00am Police confirm a 26-year-old man has been arrested and two other people involved in the incident are now safe and well.
11.30pm Officers are starting to leave the scene.
Nerys McGarry, spokesperson for Lincolnshire Police, confirmed that an individual had been arrested following the conclusion of the incident.
11.26pm Lincolnshire Police have said the incident has been brought to a safe conclusion.
They say everyone involved is safe and they will now continue their investigation.
11.24pm Some lights have been turned on inside the block of flats and our reporter on the scene can now see a police officer inside the block.
11.12pm The ambulance crew has left the scene. Police officers thank them for their help.
11.05pm The scene is quietening down but there is still no sign of any of the officers from inside the flats or the people in the flat in question.
10.58pm Groups of police officers talking and more backup arriving.
10.49pm Lincolnshire Police have issued the following statement:
"Police were called to the Moorland Avenue area of Lincoln at 7.20pm on Wednesday evening in response to the activation of a police-installed alarm.
"Attending officers were met at the scene by a man in possession of what is thought to be a handgun.
"A police firearms response was initiated and a number of residents were evacuated from neighbouring properties as a precaution.
"There have been no shots fired and nobody has been injured.
"The area is currently contained and specialist police negotiators are in attendance. Police are thanking the public for their patience and co-operation during the ongoing incident."
10.43pm The Echo understands there are armed officers inside the block of flats while the outside of the property is surrounded by other officers.
10.40pm A man tells the Echo he has been living on the estate for years and has never seen anything like this.
10.37pm Lincolnshire Police have released a statement saying they are dealing with a "firearms incident".
They say that no shots have been fired and that nobody has been injured.
10.29pm People are making their way to the scene to see what is going on for themselves.
10.22pm Four more police officers with guns approach the block of flats.
10.20pm Two people have told the Echo that a woman has been shot, however this has not been confirmed by the police.
10.09pm One resident tells the Echo: "I am no longer going to live in this part of Lincoln. There is always something going on down here and I am sick of it."
10.04pm The person inside the flat which the police were focusing their attentions has just closed the curtains.
10.01pm More officers are taking up position outside the flats.
9.56pm Another police car has arrived on the scene and the ambulance has parked up away from the busier hive of activity.
9.54pm A resident tells the Echo she heard "a noise that sounded just like a gun" around two hours ago.
9.48pm Police seem to be concentrating attention on one window which has a bright light shining out of it.
9.44pm The armed officers have come back out of the block of flats and are trying a different entrance.
9.43pm Five armed officers are entering a block of flats on Shannon Avenue.
9.38pm Police appear to be surrounding a property in Shannon Avenue.
9.34pm The property in question is in Shannon Avenue, off Moorland Avenue. Another police car arrives on scene and officers talk to paramedics.
9.32pm Barking can be heard as reports of police dogs being moved into the area.
ORIGINAL Armed response officers have swooped on Moorland Avenue in Lincoln after reports of a man with a gun.
Much of the police activity is centred around the community centre and an ambulance has just arrived on scene.
Some residents have told the Echo they heard gunshots earlier this evening.
Our reporters are on the scene and we will bring you more updates as we have them.