The nation’s top intelligence official says the U.S. has seen indications of foreign hackers spying on the presidential candidates.

The activity follows a pattern noticed during the past two presidential elections.

Director of National Intelligence James Clapper says FBI and Homeland Security Department officials are working with the campaigns to help them tighten security.

Clapper said Wednesday at the Bipartisan Policy Center in Washington that the intelligence community expects more cyber threats against the campaigns.

Foreign hacking was rampant during the 2008 presidential election and President Barack Obama and Mitt Romney were targets of Chinese cyberattacks in the 2012 campaign. Experts say neither Donald Trump’s nor Hillary Clinton’s campaign networks are secure enough to stop them.

(AP)