India, Oct. 13 -- Britain's MI5 spy chief on Tuesday warned that Iran was seeking to target military sites in the UK, saying a suspected plot to attack a US-run military air base in September was "not unique".

He also raised concerns over advancing technology and said that the UK was entering a "new era of national security".

Ken McCallum, who heads the UK's domestic security service, said Tehran was looking to widen its operations beyond targeting Iranians opposed to the country's Islamic authorities, AP reported.

He said alleged Iranian-linked activities in Britain had included arson and sabotage attacks on Jewish sites, which British authorities have attributed to Iranian proxies.

"A major shift this year has been Iranian ambitions...