Armed police had to cordon off a residential area in Brighton after receiving a call about a man believed to be armed with a gun.
Residents were not allowed back into their homes until late at night
Sussex Police were alerted about the man - who had barricaded himself inside a house on Firle Road - at about 1600 BST on Thursday.
The man - believed to be in his 50s - was arrested five hours later for public order offences, police said.
They also confirmed that a number of firearms were retrieved from the house.
Dogs and reptiles
Two dogs - a rottweiler and a German shepherd - were also found inside the house in addition to a number of reptiles, including snakes.
The dogs were removed from the building by dog wardens.
About 40 officers surrounded the house and cordoned off the area as a safety precaution.
Local residents, including several children, were prevented from returning to their homes until the situation had been resolved.
They were allowed back home late on Thursday night.
A police helicopter also used a loud hailer - called a 'sky shout' - to try to make contact with the man.
On Friday, morning Sussex Police said the man was still in custody and being questioned.
Ch Supt Paul Curtis thanked residents for their co-operation and said: "We had a genuine reason to believe that the man may cause harm to himself or members of the public, so the cordons were necessary to ensure people's safety."