Several streets in Liverpool city centre were locked down on Friday morning after a man claimed to be in possession of a "suspect package".
Workers evacuated themselves from a high-rise block before police officers entered to speak to him.
He was later seen being escorted out of the building by officers, reportedly at gunpoint according the the Liverpool Echo, before he was detained.
The bomb squad also attended the scene.
A state from Merseyside Police said: "Merseyside Police can confirm that a man has been detained following an incident at a business premises in Silkhouse Court, Tithebarn Street, Liverpool today, Friday, 8 January.
"He will be taken to a police station on Merseyside where he will be questioned.
"No one has been injured during the incident and the site will remain cordoned off until a search of the premises has been completed.
"Thanks to residents, businesses and motorists for their continued patience."
Blimey! Someone's made a bomb threat outside my work!.. pic.twitter.com/p7x7vrfupN— Michael Glenning (@mikeyglenning) January 8, 2016
They said that they were called to the scene at about 10.30am today following reports of a man acting suspiciously and claiming to be in possession of a suspect package.
A statement added: "The fire alarm was activated by staff, who evacuated themselves. All employees have since been fully accounted for. The man is still inside the building and negotiators are seeking direct contact with him, in order to safely resolve the situation."
MSB Solicitors, based in the building at Silkhouse Court, tweeted about the incident:
Apologies to all clients bomb scare on 5th floor of our silkhouse court office so building evacuated.— MSB Solicitors (@MSBSolicitors) January 8, 2016
The scene looking down Tithebarn St towards the site of the bomb scare. pic.twitter.com/OY89t29HTG— Alan Weston (@alanweston) January 8, 2016