Police cordoned off the roads surrounding Scotland Yard this morning as bomb disposal officers investigated a suspect package found nearby.
St James's Park station, just yards from the police headquarters, was evacuated just before 9.55am after the suspicious item was discovered.
Pictures emerged on Twitter of a huge police cordon and bomb disposal unit at the scene.
Andrew Neather tweeted: "Holy cow - police have closed off Broadway and sent this bomb disposal robot towards PO opposite New Scotland Yard."
He later added: "Panic over: some idiot left their rucksack at the taxi rank on Caxton Street. Police have given all clear now."
Another Twitter user, Gminus, who posted a picture of the black rucksack abandoned on the pavement, said: "Suspect backpack found outside Scotland Yard."
The abandoned rucksack found near to Scotland Yard and St James's Park stationTwitter / @GaryW2015Liam R tweeted: "Bomb scare in #London #ScotlandYard, thankfully false alarm. Ordered to stay indoors though."
Transport for London’s Twitter accounts for the Circle and District line said: “St James’s Park station is closed while we respond to a security alert."
A Metropolitan Police spokesman said officers were investigating a suspect package found near to St James's Park station.
Police confirmed the incident was stood down shortly before the Tube station reopened at around 10.20am.