WASHINGTON (REUTERS) - US presidential campaigns face threats from hackers bent on espionage and other activity more nefarious than political mischief, the office of the US National Intelligence director James Clapper said on Wednesday, but did not provide details on specific intrusions.
"We're aware that campaigns and related organisations and individuals are targeted by actors with a variety of motivations - from philosophical differences to espionage - and capabilities - from defacements to intrusions," Clapper's spokesman Brian Hale said in a statement, deferring to the FBI for details on specific incidents.
Earlier, Clapper said the US intelligence community had "already had some indications" of hacking attempts against presidential campaigns.
"As the campaign intensifies we'll probably have more"attacks, Clapper said at a morning event at the Bipartisan Policy Centre in Washington.
The last two US presidential cycles in 2008 and 2012 witnessed a barrage of cyber attacks from a range of adversaries targeting President Barack Obama's campaign and the campaigns of his Republican foes.
US intelligence officials have said many of the previous assaults were linked to Chinese hackers.
Clapper said the Department of Homeland Security and the Federal Bureau of Investigation are working to educate "both campaigns" about cyber threats, likely referring to the campaigns of presumptive Republican nominee Donald Trump and Democratic frontrunner Hillary Clinton.
Hotel properties belonging to Trump have been hacked two times since the billionaire real estate developer declared his candidacy last year. In both cases, hackers breached the credit card systems used by Trump Hotel Collection.
Clinton has endured relentless scrutiny from Republicans accusing her of jeopardising classified information by using a private e-mail server during her tenure as US secretary of state.
Clinton and US officials have said no evidence has emerged showing the server was hacked, however.
The Republican and Democratic candidates for president will begin receiving intelligence briefings after being officially nominated by their respective party at conventions this summer.
Clapper said the two candidates would receive "exactly the same" briefings. He said the sessions would not be used to try to persuade Trump to soften his stance about a proposed ban on Muslim immigration, which some national security professionals have said is counterproductive to fighting Islamic extremism.
"We've been doing this for many years, it's not designed to shape anybody's worldview," Clapper said.