Two men are being held after shots were fired during what was thought to have been a newspaper deal to buy a stolen copy of the new Harry Potter novel.
Armed police surrounded a house after shots were heard
Police were called to Tresham Street in Kettering, Northants, on Friday morning after reports a weapon had been fired.
Police said a person "in possession of firearms" had tried to sell a copy of the new Potter novel, but no weapon had yet been found despite a search.
The Sun newspaper said it had intended to obtain the book and inform police.
Surrounding streets were shut as armed officers looked for the gun involved following the incident, a Northamptonshire Police spokesman said.
Two men aged 37 and 19 from Kettering were held, and two books were recovered.
The police spokesman said: "A firearms operation was launched at a residential address in Kettering town centre which resulted in two men being arrested on suspicion of theft and firearms offences."
A spokesman for The Sun said the paper had been approached by someone claiming to have a copy of JK Rowling's latest novel.
He said: "A reporter and photographer met with two men with the intention of obtaining the book so it could be returned to the publisher and the police could be informed."
Harry Potter and the Half-Blood Prince, Rowling's sixth book, is published on 16 July.
It has sparked huge interest because of Rowling's revelation that a major character would be killed off.
Bookmakers were forced to suspend betting on the victim's identity late last month amid fears that the manuscript had been leaked.
Suspicions were aroused because of a string of bets on the death of the Hogwarts head teacher, Professor Dumbledore.
The flurry of bets came from the town of Bungay in Suffolk, where it is thought the book is being printed.