Hackers suspected to be working for Russian intelligence agencies have targeted a number of US news outlets, including the New York Times, according to reports from CNN and later confirmed by the newspaper.

CNN said that the FBI was investigating the attacks, which are thought to be part of wider series of hacks on US organizations that include the Democratic National Committee (DNC). Sensitive emails stolen from the DNC were released by Wikileaks in the run-up to the party's convention back in July.

It's rumored that the hacks came in the form of spear phishing attacks - email spoofing fraud attempts that appear to originate from trusted sources but actually contain malicious software or links to fake websites. The method could be used to gain reporters' online credentials and gather confidential information, such as the details of their government contacts.

The Times said email services for employees are outsourced to Google, and that none of the attacks had been successful.

"We are constantly monitoring our systems with the latest available intelligence and tools," said Times spokeswoman Eileen Murphy. "We have seen no evidence that any of our internal systems, including our systems in the Moscow bureau, have been breached or compromised."

The FBI's investigation into the DNC hack has since been expanded to include the reported breach of the Democratic Congressional Campaign Committee. The Times reports that once the investigation is complete, President Obama will decide if there is enough evidence to accuse Russia's government or any of its agencies publicly.