爆炸发生在当地时间夜晚9点50分左右，地铁站的工作人员感觉到震动，驾车经过该地区的人也感觉到他们的汽车受到震动。据一个目击者说，他看到一座大楼的顶层发出一下很强的闪光，然后是一声巨响。警方随后就全面封锁了军情六处总部大楼方圆一公里地段，英国反恐怖特种部队也奉命赶到现场，迅速对这起离奇爆炸事件的原因进行现场勘察。由于英国政府和有关部门对这起爆炸事件的原因和具体情况封锁得相当严密，所以媒体至今未能了解到这起爆炸事件发生的真正原因。

"MI6" redirects here. For other uses, see MI-6 (disambiguation).

"Her Majesty's Secret Service" redirects here. For other uses, see On Her Majesty's Secret Service (disambiguation). Not to be confused with MI5.

The Secret Intelligence Service (SIS) supplies the British Government with foreign intelligence. It operates under the formal direction of the Joint Intelligence Committee (JIC) alongside the internal Security Service (MI5), the Government Communications Headquarters (GCHQ) and the Defence Intelligence (

It is frequently referred to by the name MI6 (Military Intelligence, Section 6), a name used as a flag of convenience during the Second World War when it was known by many names.[1] The existence of MI6 was not officially acknowledged until 1994.[2]

In late 2010, the head of SIS delivered what he said was the first public address by a serving chief of the agency in its 101-year history. The remarks of Sir John Sawers primarily focused on the relationship between the need for secrecy and the goal of maintaining security within Britain. His remarks acknowledged the tensions caused by secrecy in an era of leaks and pressure for ever-greater disclosure.[

The service is derived from the Secret Service Bureau, which was founded in 1909.[1] The Bureau was a joint initiative of the Admiralty and the War Office to control secret intelligence operations in the UK and overseas, particularly concentrating on the activities of the Imperial German Government. The bureau was split into naval and army sections which, over time, specialised in foreign espionage and internal counter-espionage activities respectively. This specialisation was because the Admiralty wanted to know the maritime strength of the Imperial German Navy. This specialisation was formalised before 1914. When the First World War started, the two sections underwent administrative changes so that the foreign section became the Directorate of Military Intelligence Section 6 (MI6), the name by which it is frequently known in popular culture today.

Its first director was Captain Sir George Mansfield Smith-Cumming, who often dropped the Smith in routine communication. He typically signed correspondence with his initial C in green ink. This usage evolved as a code name, and has been adhered to by all subsequent directors of SIS when signing documents to retain anonymity.[1][7][8]

The service's performance during First World War was mixed, because it was unable to establish a network in Germany itself. Most of its results came from military and commercial intelligence collected through networks in neutral countries, occupied territories, and Russia.[9]

After the war, resources were significantly reduced but during the 1920s, SIS established a close operational relationship with the diplomatic service. In August 1919 Cumming created the new passport control department, providing diplomatic cover for agents abroad. The post of Passport Control Officer provided operatives with diplomatic immunity.

Circulating Sections established intelligence requirements and passed the intelligence back to its consumer departments, mainly the War Office and Admiralty.

The debate over the future structure of British Intelligence continued at length after the end of hostilities but Cumming managed to engineer the return of the Service to Foreign Office control. At this time, the organisation was known in Whitehall by a variety of titles including the Foreign Intelligence Service, the Secret Service, MI1(c), the Special Intelligence Service and even C's organisation. Around 1920, it began increasingly to be referred to as the Secret Intelligence Service (SIS), a title that it has continued to use to the present day and which was enshrined in statute in the Intelligence Services Act 1994.[1]

In the immediate post-war years under Sir George Mansfield Smith-Cumming and throughout most of the 1920s, the SIS was focused on Communism, in particular, Russian Bolshevism. Examples include a thwarted operation to overthrow the Bolshevik government[11] in 1918 by SIS agents Sidney George Reilly[12] and Sir Robert Bruce Lockhart,[13] as well as more orthodox espionage efforts within early Soviet Russia headed by Captain George Hill.

Smith-Cumming died suddenly at his home on 14 June 1923, shortly before he was due to retire, and was replaced as C by Admiral Sir Hugh "Quex" Sinclair. Sinclair created the following sections:
A central foreign counter-espionage Circulating Section, Section V, to liaise with the Security Service to collate counter-espionage reports from overseas stations.
An economic intelligence section, Section VII, to deal with trade, industrial and contraband.
A clandestine radio communications organisation, Section VIII, to communicate with operatives and agents overseas.
Section N to exploit the contents of foreign diplomatic bags
Section D to conduct political covert actions and paramilitary operations in time of war. Section D would come to be the foundation of the Special Operations Executive (SOE) during the Second World War.[10]