People took to Twitter saying they have been asked to move away from windows in the area.

St Martin Le Grand, New Change and Cheapside were closed.

Passers-by were urged to stay away.

They ordered office workers to stay inside while they investigated.

Police were called to St Martin's Le Grand, a street near the central London landmark, around 10.30am.

CORDON: People were ordered to stay inside offices in the area

One said: "Just heard controlled explosion of suspicious package at Tescos at St Paul's."

And another social media user wrote: "So the police are blocking off all the roads in St Paul's and my office is right in the middle of it."

St Paul’s Tube station was also closed while police looked into the incident.

It has since reopened.