Washington:The US government continues to investigate the extent and origin of a cyberattack that compromised the personal information of four million current and former federal employees, the White House has said.

\"No conclusions about the attribution of this particular attack have been reached at this point,\" White House spokesman Josh Earnest told reporters at his daily briefing when asked about officials placing the blame on Chinese hackers.

Officials are trying to determine whether the attack on the government\'s Office of Personnel Management was carried out on behalf of a state, the spokesman said.

He referred, however, to previous comments from President Barack Obama expressing concerns about China\'s activities in cyberspace and said the administration would continue to raise the issue with Beijing.

Earnest said authorities may ultimately decide not to disclose what they learn about the origin of the hack.

\"Even if a conclusion is reached about who is responsible, I can\'t guarantee necessarily that our law enforcement professionals will assess that making that information public is in the best interest of their investigation,\" he said.

China on Friday pointed to a lack of \"scientific evidence\" linking Chinese individuals or entities to the attack, which began in December but was only detected last month.

US still investigating origin of cyberattack: White House