A man believed to be carrying a gun was arrested at St Paul's Cathedral this afternoon - more than three hours after police first rushed to his reported location in a different part of London.

Metropolitan and City of London officers were called to an address at Curtain Road in Shoreditch at 8.30am following claims of a man with a firearm.

But after searching the area and finding no sign of the suspected gunman, police detained who they believe to be the same man just after midday, 1.3 miles away outside St Paul's.

A cordon was put in place after police arrested a man in the grounds of St Paul's Cathedral following reports someone was seen carrying a gun

Officers were called to an address at Curtain Road in Shoreditch at 8.30am following claims of a man with a firearm. But they detained who they believe to be the same man just after midday, 1.3 miles away outside St Paul's

Social media photos show a cordon in place near the iconic building and popular tourist attraction with alarmed passers-by watching.

A firearm was recovered from the scene, although police are yet to determine whether it is real or a replica.

The arrested suspect is also 'not co-operating' with officers.

City of London police said: 'Following reports of an armed man at St Paul's Cathedral, we can confirm we've arrested a man who we believe to be in possession of a firearm at 12.05 today.

Shocked onlookers watched as the man was arrested by police near the famous cathedral at lunchtime today

'He was detained behind One New Change by armed officers. There is no indication this incident is terror-related at this time.

'Officers from both the City of London Police and Met Police attended a domestic-related incident this morning at 08:30 on Curtain Road (EC2A).

'This was following a report of a man in possession of a firearm. An investigation began immediately to locate this individual.

'We are now confident the man arrested at St Paul's this afternoon is the same individual.

'He currently remains in police custody and officers are not looking for anyone else in relation to the incidents.'