Media playback is unsupported on your device Media caption Hillary Clinton: "[China] are also trying to hack into everything that doesn't move in America"

US Democratic presidential hopeful Hillary Clinton has accused China of stealing commercial secrets and government information.

She accused China of "trying to hack into everything that doesn't move in America", and urged vigilance.

US officials had named China as the chief suspect in the massive hack of the records of a US government agency earlier this year.

China had denied any involvement, and called US claims "irresponsible".

'Fully vigilant'

Speaking at a campaign event in New Hampshire, Ms Clinton said that China was stealing secrets from defence contractors and had taken "huge amounts of government information, all looking for an advantage."

She added that she wanted to see China's peaceful rise but that the US needed to stay "fully vigilant".

"China's military is growing very quickly, they're establishing military installations that again threaten countries we have treaties with, like the Philippines because they are building on contested property," she said.

Image copyright Reuters Image caption The hacking of federal government computers may have compromised the records of four million people

US officials have blamed China for a major data breach of the Office of Personnel Management (OPM) that was revealed in June.

The hacking of federal government computers could have compromised the records of four million employees.

US intelligence chief James Clapper called China a "leading suspect" after the incident.

But China dismissed the accusation, saying that it was "irresponsible and unscientific".

China has previously argued that it is also the victim of hacking attacks.

Republican presidential candidates have used the recent OPM cyber hack to attack President Obama's administration, accusing it of "incompetence".

Marco Rubio and Rick Perry have called for the US to threaten sanctions against organisations linked to hacking, while Mike Huckabee has argued that the US should "hack China back".

Meanwhile, Democratic candidate Martin O'Malley has called for better funding for cyber security.

The hack against the OPM is not the first time that China has been blamed for a cyber attack against the US.

An earlier attempt to breach OPM networks was blocked in March 2014, with the US saying China was behind the attack.

Previous hack attacks on US government