Russia¡¯s GRU military intelligence service is seeking to cause ¡°mayhem¡± across Britain and Europe, the U.K.¡¯s domestic spy chief said on Tuesday, while underlining a growing threat from resurgent al-Qaeda and the Islamic State group as his greatest terrorism concern.

In a wide-ranging speech outlining the current threat picture, Security Service (MI5) Director General Ken McCallum also accused Iran of being behind ¡°plot after plot¡± on British soil.

McCallum said state threat investigations were up 48% in the last year as Russia and Iran turned to criminals, drug traffickers and proxies to carry out their ¡°dirty work.¡±