Armed police cordoned off a street when a woman threatened walkers with a toy gun.
Terrified residents called police as the woman waved what appeared to be a pistol from the balcony of a flat, shouting she was going to shoot people.
Police cordoned off the area in Tichborne Street in central Brighton, at 8pm on Sunday as officers entered the flat.
A Sussex Police spokesman said two men had been detained and were helping police with enquiries. They are looking for the woman, who is known to police and had gone when police arrived.
Two toy guns, one of which matched the description of the ‘pistol’, were found in the flat and have been seized. No one was hurt. Chief Inspector Dave Padwick, of Sussex Police, said: “What started as a serious incident was eventually found to involve a toy gun.
“However, public safety is paramount in such situations and that is why armed police attended and the area was made secure. We are grateful to residents for their trust and patience.”