Police have closed off a number of streets in the centre of Liverpool after a man claiming to be in possession of a bomb sparked a possible terror threat at a high-rise building.

A fire alarm was triggered by employees at the Silkhouse Court building on Tithebarn Street in the city centre, after which police evacuated it and a number of nearby streets and dispatched a helicopter.

In a statement, Merseyside Police said all employees in the building had been accounted for and the man, who had been "acting suspiciously" was still inside.

According to the Liverpool Echo, police negotiators are attempting to speak to the man, while a bomb disposal team has arrived at the scene.

"Merseyside Police is dealing with a security alert at a business premises in Silkhouse Court, Tithebarn Street, Liverpool," a police statement read. "Officers 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.

"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.

Local reporters said the unusually large police presence in response to the initial fire alarm had raised concerns among residents.

The police statement said no one had been injured, and described the police cordon around the building as "a safety precaution"

It said: "There are a number of road closures in place, they are Tithebarn Street, Old Hall Street at the junction with Union Street. Police are advising motorists to avoid the area. There is also disruption at Chapel Street, George Street and Exchange Street at the junction of Dale Street."