Police and emergency services were called to investigate after witnesses reported the sound of a loud "explosion" in Stockholm on Friday.
The mystery bang was heard at 11.40am around Brännkyrkagatan on Södermalm island, an area of the capital which is known for its range of trendy restaurants and hipster shops.
"We're there to investigate what has happened but at the moment it is unclear," police press spokesman Albin Näverberg told the Aftonbladet tabloid.
Swedish and international media rushed to report the apparent explosion, which could not be heard from The Local's office less than two kilometres from the scene of the blast.
The street was closed off while police investigated, but the cordons were lifted shortly thereafter when officers were unable to find the source of the alleged blast and there were no reports of injuries.
Nearby buildings and cars were checked but were not found to have been damaged. Officers reported that one window on the street was broken, but did not believe it was connected to the incident.
"The apartment owner had a broken window, it doesn't seem to be connected to any bang. He was at home himself putting up curtains," Näverberg told public broadcaster SVT.
But according to unnamed sources cited by Aftonbladet later in the afternoon the apartment owner was in fact the source behind the mystery blast.
The newspaper wrote that the man had accidentally dropped a large drill when he was hanging up his curtains, which broke the window and fell on to a tin roof – causing the loud bang.
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According to Aftonbladet, police were called to the scene believing they had a hostage situation on their hands after witnesses reported seeing "a man in a window", mistaking his drill for "a gun-like object".
It is not the first time this year officers have been called out to incidents which turned out to bear little relation to criminal activity. In June The Local spoke to a dad carrying his son, who was mistaken for a burglar carrying his loot, because he had grown a beard on paternity leave.
And in February police were alerted when a young woman's neighbours confused her 21st birthday balloons with propaganda for the extremist group Isis, also known as IS.